diff --git a/src/core/ext/filters/client_channel/client_channel.cc b/src/core/ext/filters/client_channel/client_channel.cc
index 7292184bf71..fec5fd952fb 100644
--- a/src/core/ext/filters/client_channel/client_channel.cc
+++ b/src/core/ext/filters/client_channel/client_channel.cc
@@ -209,7 +209,7 @@ class ChannelData {
                                 grpc_closure* on_complete,
                                 grpc_closure* watcher_timer_init);
 
-    ~ExternalConnectivityWatcher();
+    ~ExternalConnectivityWatcher() override;
 
     // Removes the watcher from the external_watchers_ map.
     static void RemoveWatcherFromExternalWatchersMap(ChannelData* chand,
@@ -919,7 +919,7 @@ class ChannelData::SubchannelWrapper : public SubchannelInterface {
     chand_->subchannel_wrappers_.insert(this);
   }
 
-  ~SubchannelWrapper() {
+  ~SubchannelWrapper() override {
     if (GRPC_TRACE_FLAG_ENABLED(grpc_client_channel_routing_trace)) {
       gpr_log(GPR_INFO,
               "chand=%p: destroying subchannel wrapper %p for subchannel %p",
@@ -1062,7 +1062,7 @@ class ChannelData::SubchannelWrapper : public SubchannelInterface {
           parent_(std::move(parent)),
           last_seen_state_(initial_state) {}
 
-    ~WatcherWrapper() {
+    ~WatcherWrapper() override {
       auto* parent = parent_.release();  // ref owned by lambda
       parent->chand_->work_serializer_->Run(
           [parent]() { parent->Unref(DEBUG_LOCATION, "WatcherWrapper"); },
diff --git a/src/core/ext/filters/client_channel/config_selector.h b/src/core/ext/filters/client_channel/config_selector.h
index 17c14daa4ae..54e6bd5d0c6 100644
--- a/src/core/ext/filters/client_channel/config_selector.h
+++ b/src/core/ext/filters/client_channel/config_selector.h
@@ -65,7 +65,7 @@ class ConfigSelector : public RefCounted<ConfigSelector> {
     std::function<void()> on_call_committed;
   };
 
-  virtual ~ConfigSelector() = default;
+  ~ConfigSelector() override = default;
 
   virtual const char* name() const = 0;
 
diff --git a/src/core/ext/filters/client_channel/health/health_check_client.h b/src/core/ext/filters/client_channel/health/health_check_client.h
index e9555b5f955..24b59c7c5f4 100644
--- a/src/core/ext/filters/client_channel/health/health_check_client.h
+++ b/src/core/ext/filters/client_channel/health/health_check_client.h
@@ -50,7 +50,7 @@ class HealthCheckClient : public InternallyRefCounted<HealthCheckClient> {
                     RefCountedPtr<channelz::SubchannelNode> channelz_node,
                     RefCountedPtr<ConnectivityStateWatcherInterface> watcher);
 
-  ~HealthCheckClient();
+  ~HealthCheckClient() override;
 
   void Orphan() override;
 
@@ -60,7 +60,7 @@ class HealthCheckClient : public InternallyRefCounted<HealthCheckClient> {
    public:
     CallState(RefCountedPtr<HealthCheckClient> health_check_client,
               grpc_pollset_set* interested_parties_);
-    ~CallState();
+    ~CallState() override;
 
     void Orphan() override;
 
diff --git a/src/core/ext/filters/client_channel/http_connect_handshaker.cc b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
index 620cc89e334..1b9817cee78 100644
--- a/src/core/ext/filters/client_channel/http_connect_handshaker.cc
+++ b/src/core/ext/filters/client_channel/http_connect_handshaker.cc
@@ -54,7 +54,7 @@ class HttpConnectHandshaker : public Handshaker {
   const char* name() const override { return "http_connect"; }
 
  private:
-  virtual ~HttpConnectHandshaker();
+  ~HttpConnectHandshaker() override;
   void CleanupArgsForFailureLocked();
   void HandshakeFailedLocked(grpc_error* error);
   static void OnWriteDone(void* arg, grpc_error* error);
diff --git a/src/core/ext/filters/client_channel/lb_policy.h b/src/core/ext/filters/client_channel/lb_policy.h
index e132564bc38..13c315e0bf5 100644
--- a/src/core/ext/filters/client_channel/lb_policy.h
+++ b/src/core/ext/filters/client_channel/lb_policy.h
@@ -301,7 +301,7 @@ class LoadBalancingPolicy : public InternallyRefCounted<LoadBalancingPolicy> {
   /// return the parameters they need.
   class Config : public RefCounted<Config> {
    public:
-    virtual ~Config() = default;
+    ~Config() override = default;
 
     // Returns the load balancing policy name
     virtual const char* name() const = 0;
@@ -341,7 +341,7 @@ class LoadBalancingPolicy : public InternallyRefCounted<LoadBalancingPolicy> {
   };
 
   explicit LoadBalancingPolicy(Args args, intptr_t initial_refcount = 1);
-  virtual ~LoadBalancingPolicy();
+  ~LoadBalancingPolicy() override;
 
   // Not copyable nor movable.
   LoadBalancingPolicy(const LoadBalancingPolicy&) = delete;
@@ -376,7 +376,7 @@ class LoadBalancingPolicy : public InternallyRefCounted<LoadBalancingPolicy> {
     explicit QueuePicker(RefCountedPtr<LoadBalancingPolicy> parent)
         : parent_(std::move(parent)) {}
 
-    ~QueuePicker() { parent_.reset(DEBUG_LOCATION, "QueuePicker"); }
+    ~QueuePicker() override { parent_.reset(DEBUG_LOCATION, "QueuePicker"); }
 
     PickResult Pick(PickArgs args) override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.cc b/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.cc
index 2ca1573af6a..0edf61db1bb 100644
--- a/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.cc
@@ -36,7 +36,7 @@ class ChildPolicyHandler::Helper
   explicit Helper(RefCountedPtr<ChildPolicyHandler> parent)
       : parent_(std::move(parent)) {}
 
-  ~Helper() { parent_.reset(DEBUG_LOCATION, "Helper"); }
+  ~Helper() override { parent_.reset(DEBUG_LOCATION, "Helper"); }
 
   RefCountedPtr<SubchannelInterface> CreateSubchannel(
       ServerAddress address, const grpc_channel_args& args) override {
diff --git a/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.h b/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.h
index d67f3264a87..c902c0ec8d6 100644
--- a/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.h
+++ b/src/core/ext/filters/client_channel/lb_policy/child_policy_handler.h
@@ -36,7 +36,7 @@ class ChildPolicyHandler : public LoadBalancingPolicy {
   ChildPolicyHandler(Args args, TraceFlag* tracer)
       : LoadBalancingPolicy(std::move(args)), tracer_(tracer) {}
 
-  virtual const char* name() const override { return "child_policy_handler"; }
+  const char* name() const override { return "child_policy_handler"; }
 
   void UpdateLocked(UpdateArgs args) override;
   void ExitIdleLocked() override;
diff --git a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
index c9f1d4db9f7..3ef86206751 100644
--- a/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/grpclb/grpclb.cc
@@ -164,7 +164,7 @@ class GrpcLb : public LoadBalancingPolicy {
    public:
     explicit BalancerCallState(
         RefCountedPtr<LoadBalancingPolicy> parent_grpclb_policy);
-    ~BalancerCallState();
+    ~BalancerCallState() override;
 
     // It's the caller's responsibility to ensure that Orphan() is called from
     // inside the combiner.
@@ -369,7 +369,7 @@ class GrpcLb : public LoadBalancingPolicy {
         : AsyncConnectivityStateWatcherInterface(parent->work_serializer()),
           parent_(std::move(parent)) {}
 
-    ~StateWatcher() { parent_.reset(DEBUG_LOCATION, "StateWatcher"); }
+    ~StateWatcher() override { parent_.reset(DEBUG_LOCATION, "StateWatcher"); }
 
    private:
     void OnConnectivityStateChange(grpc_connectivity_state new_state,
@@ -395,7 +395,7 @@ class GrpcLb : public LoadBalancingPolicy {
     RefCountedPtr<GrpcLb> parent_;
   };
 
-  ~GrpcLb();
+  ~GrpcLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
index 784e964960f..8b64f2b4e37 100644
--- a/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/pick_first/pick_first.cc
@@ -55,7 +55,7 @@ class PickFirst : public LoadBalancingPolicy {
   void ResetBackoffLocked() override;
 
  private:
-  ~PickFirst();
+  ~PickFirst() override;
 
   class PickFirstSubchannelList;
 
@@ -94,7 +94,7 @@ class PickFirst : public LoadBalancingPolicy {
       policy->Ref(DEBUG_LOCATION, "subchannel_list").release();
     }
 
-    ~PickFirstSubchannelList() {
+    ~PickFirstSubchannelList() override {
       PickFirst* p = static_cast<PickFirst*>(policy());
       p->Unref(DEBUG_LOCATION, "subchannel_list");
     }
diff --git a/src/core/ext/filters/client_channel/lb_policy/priority/priority.cc b/src/core/ext/filters/client_channel/lb_policy/priority/priority.cc
index 07a7b2700cb..95df80b1caf 100644
--- a/src/core/ext/filters/client_channel/lb_policy/priority/priority.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/priority/priority.cc
@@ -93,7 +93,7 @@ class PriorityLb : public LoadBalancingPolicy {
    public:
     ChildPriority(RefCountedPtr<PriorityLb> priority_policy, std::string name);
 
-    ~ChildPriority() {
+    ~ChildPriority() override {
       priority_policy_.reset(DEBUG_LOCATION, "ChildPriority");
     }
 
@@ -152,7 +152,7 @@ class PriorityLb : public LoadBalancingPolicy {
       explicit Helper(RefCountedPtr<ChildPriority> priority)
           : priority_(std::move(priority)) {}
 
-      ~Helper() { priority_.reset(DEBUG_LOCATION, "Helper"); }
+      ~Helper() override { priority_.reset(DEBUG_LOCATION, "Helper"); }
 
       RefCountedPtr<SubchannelInterface> CreateSubchannel(
           ServerAddress address, const grpc_channel_args& args) override;
@@ -202,7 +202,7 @@ class PriorityLb : public LoadBalancingPolicy {
     bool failover_timer_callback_pending_ = false;
   };
 
-  ~PriorityLb();
+  ~PriorityLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
index 6dc107702e3..efc7942a6a0 100644
--- a/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/round_robin/round_robin.cc
@@ -65,7 +65,7 @@ class RoundRobin : public LoadBalancingPolicy {
   void ResetBackoffLocked() override;
 
  private:
-  ~RoundRobin();
+  ~RoundRobin() override;
 
   // Forward declaration.
   class RoundRobinSubchannelList;
@@ -122,7 +122,7 @@ class RoundRobin : public LoadBalancingPolicy {
       policy->Ref(DEBUG_LOCATION, "subchannel_list").release();
     }
 
-    ~RoundRobinSubchannelList() {
+    ~RoundRobinSubchannelList() override {
       RoundRobin* p = static_cast<RoundRobin*>(policy());
       p->Unref(DEBUG_LOCATION, "subchannel_list");
     }
diff --git a/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h b/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
index 56ff2ab6364..a240a2d0e17 100644
--- a/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
+++ b/src/core/ext/filters/client_channel/lb_policy/subchannel_list.h
@@ -142,7 +142,9 @@ class SubchannelData {
         : subchannel_data_(subchannel_data),
           subchannel_list_(std::move(subchannel_list)) {}
 
-    ~Watcher() { subchannel_list_.reset(DEBUG_LOCATION, "Watcher dtor"); }
+    ~Watcher() override {
+      subchannel_list_.reset(DEBUG_LOCATION, "Watcher dtor");
+    }
 
     void OnConnectivityStateChange(grpc_connectivity_state new_state) override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/weighted_target/weighted_target.cc b/src/core/ext/filters/client_channel/lb_policy/weighted_target/weighted_target.cc
index 0f99692da5c..1eca478b488 100644
--- a/src/core/ext/filters/client_channel/lb_policy/weighted_target/weighted_target.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/weighted_target/weighted_target.cc
@@ -118,7 +118,7 @@ class WeightedTargetLb : public LoadBalancingPolicy {
    public:
     WeightedChild(RefCountedPtr<WeightedTargetLb> weighted_target_policy,
                   const std::string& name);
-    ~WeightedChild();
+    ~WeightedChild() override;
 
     void Orphan() override;
 
@@ -142,7 +142,7 @@ class WeightedTargetLb : public LoadBalancingPolicy {
       explicit Helper(RefCountedPtr<WeightedChild> weighted_child)
           : weighted_child_(std::move(weighted_child)) {}
 
-      ~Helper() { weighted_child_.reset(DEBUG_LOCATION, "Helper"); }
+      ~Helper() override { weighted_child_.reset(DEBUG_LOCATION, "Helper"); }
 
       RefCountedPtr<SubchannelInterface> CreateSubchannel(
           ServerAddress address, const grpc_channel_args& args) override;
@@ -188,7 +188,7 @@ class WeightedTargetLb : public LoadBalancingPolicy {
     bool shutdown_ = false;
   };
 
-  ~WeightedTargetLb();
+  ~WeightedTargetLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/xds/cds.cc b/src/core/ext/filters/client_channel/lb_policy/xds/cds.cc
index da048b553d1..bb336d7df21 100644
--- a/src/core/ext/filters/client_channel/lb_policy/xds/cds.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/xds/cds.cc
@@ -113,7 +113,7 @@ class CdsLb : public LoadBalancingPolicy {
     RefCountedPtr<CdsLb> parent_;
   };
 
-  ~CdsLb();
+  ~CdsLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/xds/eds.cc b/src/core/ext/filters/client_channel/lb_policy/xds/eds.cc
index 3eeac4ef63e..5d7946c0b36 100644
--- a/src/core/ext/filters/client_channel/lb_policy/xds/eds.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/xds/eds.cc
@@ -144,7 +144,7 @@ class EdsLb : public LoadBalancingPolicy {
     explicit Helper(RefCountedPtr<EdsLb> eds_policy)
         : eds_policy_(std::move(eds_policy)) {}
 
-    ~Helper() { eds_policy_.reset(DEBUG_LOCATION, "Helper"); }
+    ~Helper() override { eds_policy_.reset(DEBUG_LOCATION, "Helper"); }
 
     RefCountedPtr<SubchannelInterface> CreateSubchannel(
         ServerAddress address, const grpc_channel_args& args) override;
@@ -160,7 +160,7 @@ class EdsLb : public LoadBalancingPolicy {
     RefCountedPtr<EdsLb> eds_policy_;
   };
 
-  ~EdsLb();
+  ~EdsLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc b/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc
index 506d4623f97..ad2f61cffb0 100644
--- a/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_impl.cc
@@ -141,7 +141,7 @@ class XdsClusterImplLb : public LoadBalancingPolicy {
     Picker(RefCountedPtr<XdsClusterImplLb> xds_cluster_impl_lb,
            RefCountedPtr<RefCountedPicker> picker);
 
-    PickResult Pick(PickArgs args);
+    PickResult Pick(PickArgs args) override;
 
    private:
     RefCountedPtr<XdsClusterImplLb> xds_cluster_impl_lb_;
@@ -157,7 +157,9 @@ class XdsClusterImplLb : public LoadBalancingPolicy {
     explicit Helper(RefCountedPtr<XdsClusterImplLb> xds_cluster_impl_policy)
         : xds_cluster_impl_policy_(std::move(xds_cluster_impl_policy)) {}
 
-    ~Helper() { xds_cluster_impl_policy_.reset(DEBUG_LOCATION, "Helper"); }
+    ~Helper() override {
+      xds_cluster_impl_policy_.reset(DEBUG_LOCATION, "Helper");
+    }
 
     RefCountedPtr<SubchannelInterface> CreateSubchannel(
         ServerAddress address, const grpc_channel_args& args) override;
@@ -171,7 +173,7 @@ class XdsClusterImplLb : public LoadBalancingPolicy {
     RefCountedPtr<XdsClusterImplLb> xds_cluster_impl_policy_;
   };
 
-  ~XdsClusterImplLb();
+  ~XdsClusterImplLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc b/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc
index 4363c86c10b..d4d3fb7c517 100644
--- a/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc
+++ b/src/core/ext/filters/client_channel/lb_policy/xds/xds_cluster_manager.cc
@@ -117,7 +117,7 @@ class XdsClusterManagerLb : public LoadBalancingPolicy {
    public:
     ClusterChild(RefCountedPtr<XdsClusterManagerLb> xds_cluster_manager_policy,
                  const std::string& name);
-    ~ClusterChild();
+    ~ClusterChild() override;
 
     void Orphan() override;
 
@@ -141,7 +141,9 @@ class XdsClusterManagerLb : public LoadBalancingPolicy {
       explicit Helper(RefCountedPtr<ClusterChild> xds_cluster_manager_child)
           : xds_cluster_manager_child_(std::move(xds_cluster_manager_child)) {}
 
-      ~Helper() { xds_cluster_manager_child_.reset(DEBUG_LOCATION, "Helper"); }
+      ~Helper() override {
+        xds_cluster_manager_child_.reset(DEBUG_LOCATION, "Helper");
+      }
 
       RefCountedPtr<SubchannelInterface> CreateSubchannel(
           ServerAddress address, const grpc_channel_args& args) override;
@@ -182,7 +184,7 @@ class XdsClusterManagerLb : public LoadBalancingPolicy {
     bool shutdown_ = false;
   };
 
-  ~XdsClusterManagerLb();
+  ~XdsClusterManagerLb() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/resolver.h b/src/core/ext/filters/client_channel/resolver.h
index de941a063b4..6c0a8efd9d9 100644
--- a/src/core/ext/filters/client_channel/resolver.h
+++ b/src/core/ext/filters/client_channel/resolver.h
@@ -87,7 +87,7 @@ class Resolver : public InternallyRefCounted<Resolver> {
   // Not copyable nor movable.
   Resolver(const Resolver&) = delete;
   Resolver& operator=(const Resolver&) = delete;
-  virtual ~Resolver() = default;
+  ~Resolver() override = default;
 
   /// Starts resolving.
   virtual void StartLocked() = 0;
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
index c5439717c09..f0bf0cda2fe 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/dns_resolver_ares.cc
@@ -75,7 +75,7 @@ class AresDnsResolver : public Resolver {
   void ShutdownLocked() override;
 
  private:
-  virtual ~AresDnsResolver();
+  ~AresDnsResolver() override;
 
   void MaybeStartResolvingLocked();
   void StartResolvingLocked();
diff --git a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
index 6659dc157b1..062f4830e31 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.cc
@@ -49,7 +49,7 @@ class GrpcPolledFdPosix : public GrpcPolledFd {
     grpc_pollset_set_add_fd(driver_pollset_set_, fd_);
   }
 
-  ~GrpcPolledFdPosix() {
+  ~GrpcPolledFdPosix() override {
     grpc_pollset_set_del_fd(driver_pollset_set_, fd_);
     /* c-ares library will close the fd inside grpc_fd. This fd may be picked up
        immediately by another thread, and should not be closed by the following
diff --git a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
index 3b0c042d292..e17d84f414d 100644
--- a/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/dns/native/dns_resolver.cc
@@ -63,7 +63,7 @@ class NativeDnsResolver : public Resolver {
   void ShutdownLocked() override;
 
  private:
-  virtual ~NativeDnsResolver();
+  ~NativeDnsResolver() override;
 
   void MaybeStartResolvingLocked();
   void StartResolvingLocked();
diff --git a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
index 0bfb651a0f5..005de558ad7 100644
--- a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.cc
@@ -59,7 +59,7 @@ class FakeResolver : public Resolver {
   friend class FakeResolverResponseGenerator;
   friend class FakeResolverResponseSetter;
 
-  virtual ~FakeResolver();
+  ~FakeResolver() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h
index b9fd90c069f..b9ca69df1e0 100644
--- a/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h
+++ b/src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h
@@ -43,7 +43,7 @@ class FakeResolverResponseGenerator
     : public RefCounted<FakeResolverResponseGenerator> {
  public:
   FakeResolverResponseGenerator();
-  ~FakeResolverResponseGenerator();
+  ~FakeResolverResponseGenerator() override;
 
   // Instructs the fake resolver associated with the response generator
   // instance to trigger a new resolution with the specified result. If the
diff --git a/src/core/ext/filters/client_channel/resolver/xds/xds_resolver.cc b/src/core/ext/filters/client_channel/resolver/xds/xds_resolver.cc
index e8a7717d45a..af957f74993 100644
--- a/src/core/ext/filters/client_channel/resolver/xds/xds_resolver.cc
+++ b/src/core/ext/filters/client_channel/resolver/xds/xds_resolver.cc
@@ -140,7 +140,7 @@ class XdsResolver : public Resolver {
     XdsConfigSelector(RefCountedPtr<XdsResolver> resolver,
                       const std::vector<XdsApi::Route>& routes,
                       grpc_error* error);
-    ~XdsConfigSelector();
+    ~XdsConfigSelector() override;
 
     const char* name() const override { return "XdsConfigSelector"; }
 
diff --git a/src/core/ext/filters/client_channel/resolving_lb_policy.cc b/src/core/ext/filters/client_channel/resolving_lb_policy.cc
index 49512c5d5ab..889c20ca85c 100644
--- a/src/core/ext/filters/client_channel/resolving_lb_policy.cc
+++ b/src/core/ext/filters/client_channel/resolving_lb_policy.cc
@@ -78,7 +78,7 @@ class ResolvingLoadBalancingPolicy::ResolverResultHandler
       RefCountedPtr<ResolvingLoadBalancingPolicy> parent)
       : parent_(std::move(parent)) {}
 
-  ~ResolverResultHandler() {
+  ~ResolverResultHandler() override {
     if (GRPC_TRACE_FLAG_ENABLED(*(parent_->tracer_))) {
       gpr_log(GPR_INFO, "resolving_lb=%p: resolver shutdown complete",
               parent_.get());
diff --git a/src/core/ext/filters/client_channel/resolving_lb_policy.h b/src/core/ext/filters/client_channel/resolving_lb_policy.h
index 2835c84d707..dd592be0faa 100644
--- a/src/core/ext/filters/client_channel/resolving_lb_policy.h
+++ b/src/core/ext/filters/client_channel/resolving_lb_policy.h
@@ -83,7 +83,7 @@ class ResolvingLoadBalancingPolicy : public LoadBalancingPolicy {
                                grpc_core::UniquePtr<char> target_uri,
                                ChannelConfigHelper* helper);
 
-  virtual const char* name() const override { return "resolving_lb"; }
+  const char* name() const override { return "resolving_lb"; }
 
   // No-op -- should never get updates from the channel.
   // TODO(roth): Need to support updating child LB policy's config for xds
@@ -100,7 +100,7 @@ class ResolvingLoadBalancingPolicy : public LoadBalancingPolicy {
   class ResolverResultHandler;
   class ResolvingControlHelper;
 
-  ~ResolvingLoadBalancingPolicy();
+  ~ResolvingLoadBalancingPolicy() override;
 
   void ShutdownLocked() override;
 
diff --git a/src/core/ext/filters/client_channel/retry_throttle.h b/src/core/ext/filters/client_channel/retry_throttle.h
index 897a617f59a..e40363fd3d1 100644
--- a/src/core/ext/filters/client_channel/retry_throttle.h
+++ b/src/core/ext/filters/client_channel/retry_throttle.h
@@ -32,7 +32,7 @@ class ServerRetryThrottleData : public RefCounted<ServerRetryThrottleData> {
  public:
   ServerRetryThrottleData(intptr_t max_milli_tokens, intptr_t milli_token_ratio,
                           ServerRetryThrottleData* old_throttle_data);
-  ~ServerRetryThrottleData();
+  ~ServerRetryThrottleData() override;
 
   /// Records a failure.  Returns true if it's okay to send a retry.
   bool RecordFailure();
diff --git a/src/core/ext/filters/client_channel/service_config.h b/src/core/ext/filters/client_channel/service_config.h
index 6086a4d5203..2dfd45d8f6c 100644
--- a/src/core/ext/filters/client_channel/service_config.h
+++ b/src/core/ext/filters/client_channel/service_config.h
@@ -71,7 +71,7 @@ class ServiceConfig : public RefCounted<ServiceConfig> {
 
   ServiceConfig(const grpc_channel_args* args, std::string json_string,
                 Json json, grpc_error** error);
-  ~ServiceConfig();
+  ~ServiceConfig() override;
 
   const std::string& json_string() const { return json_string_; }
 
diff --git a/src/core/ext/filters/client_channel/subchannel.cc b/src/core/ext/filters/client_channel/subchannel.cc
index 561472d1da0..286a50e9338 100644
--- a/src/core/ext/filters/client_channel/subchannel.cc
+++ b/src/core/ext/filters/client_channel/subchannel.cc
@@ -325,7 +325,7 @@ class Subchannel::ConnectedSubchannelStateWatcher
     GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "connecting");
   }
 
-  ~ConnectedSubchannelStateWatcher() {
+  ~ConnectedSubchannelStateWatcher() override {
     GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "state_watcher");
   }
 
@@ -452,7 +452,7 @@ class Subchannel::HealthWatcherMap::HealthWatcher
     if (subchannel_state == GRPC_CHANNEL_READY) StartHealthCheckingLocked();
   }
 
-  ~HealthWatcher() {
+  ~HealthWatcher() override {
     GRPC_SUBCHANNEL_WEAK_UNREF(subchannel_, "health_watcher");
   }
 
diff --git a/src/core/ext/filters/client_channel/subchannel.h b/src/core/ext/filters/client_channel/subchannel.h
index f3de5c80747..46ffb2f25b3 100644
--- a/src/core/ext/filters/client_channel/subchannel.h
+++ b/src/core/ext/filters/client_channel/subchannel.h
@@ -76,7 +76,7 @@ class ConnectedSubchannel : public RefCounted<ConnectedSubchannel> {
   ConnectedSubchannel(
       grpc_channel_stack* channel_stack, const grpc_channel_args* args,
       RefCountedPtr<channelz::SubchannelNode> channelz_subchannel);
-  ~ConnectedSubchannel();
+  ~ConnectedSubchannel() override;
 
   void StartWatch(grpc_pollset_set* interested_parties,
                   OrphanablePtr<ConnectivityStateWatcherInterface> watcher);
@@ -186,7 +186,7 @@ class Subchannel {
       RefCountedPtr<ConnectedSubchannel> connected_subchannel;
     };
 
-    virtual ~ConnectivityStateWatcherInterface() = default;
+    ~ConnectivityStateWatcherInterface() override = default;
 
     // Will be invoked whenever the subchannel's connectivity state
     // changes.  There will be only one invocation of this method on a
diff --git a/src/core/ext/filters/client_channel/subchannel_interface.h b/src/core/ext/filters/client_channel/subchannel_interface.h
index d3a11cb301f..c1618470a2f 100644
--- a/src/core/ext/filters/client_channel/subchannel_interface.h
+++ b/src/core/ext/filters/client_channel/subchannel_interface.h
@@ -50,7 +50,7 @@ class SubchannelInterface : public RefCounted<SubchannelInterface> {
   explicit SubchannelInterface(const char* trace = nullptr)
       : RefCounted<SubchannelInterface>(trace) {}
 
-  virtual ~SubchannelInterface() = default;
+  ~SubchannelInterface() override = default;
 
   // Returns the current connectivity state of the subchannel.
   virtual grpc_connectivity_state CheckConnectivityState() = 0;
diff --git a/src/core/ext/filters/client_channel/subchannel_pool_interface.h b/src/core/ext/filters/client_channel/subchannel_pool_interface.h
index 9c48f61d399..f320ab69c26 100644
--- a/src/core/ext/filters/client_channel/subchannel_pool_interface.h
+++ b/src/core/ext/filters/client_channel/subchannel_pool_interface.h
@@ -67,7 +67,7 @@ class SubchannelPoolInterface : public RefCounted<SubchannelPoolInterface> {
       : RefCounted(GRPC_TRACE_FLAG_ENABLED(grpc_subchannel_pool_trace)
                        ? "SubchannelPoolInterface"
                        : nullptr) {}
-  virtual ~SubchannelPoolInterface() {}
+  ~SubchannelPoolInterface() override {}
 
   // Registers a subchannel against a key. Returns the subchannel registered
   // with \a key, which may be different from \a constructed because we reuse
diff --git a/src/core/ext/filters/max_age/max_age_filter.cc b/src/core/ext/filters/max_age/max_age_filter.cc
index ef59d675770..b417db51caa 100644
--- a/src/core/ext/filters/max_age/max_age_filter.cc
+++ b/src/core/ext/filters/max_age/max_age_filter.cc
@@ -224,7 +224,7 @@ class ConnectivityWatcher : public AsyncConnectivityStateWatcherInterface {
     GRPC_CHANNEL_STACK_REF(chand_->channel_stack, "max_age conn_watch");
   }
 
-  ~ConnectivityWatcher() {
+  ~ConnectivityWatcher() override {
     GRPC_CHANNEL_STACK_UNREF(chand_->channel_stack, "max_age conn_watch");
   }
 
diff --git a/src/core/ext/transport/chttp2/client/chttp2_connector.h b/src/core/ext/transport/chttp2/client/chttp2_connector.h
index 37143c8f187..7624b7f8f7e 100644
--- a/src/core/ext/transport/chttp2/client/chttp2_connector.h
+++ b/src/core/ext/transport/chttp2/client/chttp2_connector.h
@@ -30,7 +30,7 @@ namespace grpc_core {
 class Chttp2Connector : public SubchannelConnector {
  public:
   Chttp2Connector();
-  ~Chttp2Connector();
+  ~Chttp2Connector() override;
 
   void Connect(const Args& args, Result* result, grpc_closure* notify) override;
   void Shutdown(grpc_error* error) override;
diff --git a/src/core/ext/transport/chttp2/server/chttp2_server.cc b/src/core/ext/transport/chttp2/server/chttp2_server.cc
index 000c63c8786..4c63dd7f589 100644
--- a/src/core/ext/transport/chttp2/server/chttp2_server.cc
+++ b/src/core/ext/transport/chttp2/server/chttp2_server.cc
@@ -63,7 +63,7 @@ class Chttp2ServerListener : public Server::ListenerInterface {
 
   // Do not instantiate directly.  Use one of the factory methods above.
   Chttp2ServerListener(Server* server, grpc_channel_args* args);
-  ~Chttp2ServerListener();
+  ~Chttp2ServerListener() override;
 
   void Start(Server* server,
              const std::vector<grpc_pollset*>* pollsets) override;
@@ -85,7 +85,7 @@ class Chttp2ServerListener : public Server::ListenerInterface {
                     RefCountedPtr<HandshakeManager> handshake_mgr,
                     grpc_channel_args* args, grpc_endpoint* endpoint);
 
-    ~ConnectionState();
+    ~ConnectionState() override;
 
    private:
     static void OnTimeout(void* arg, grpc_error* error);
diff --git a/src/core/ext/transport/chttp2/transport/flow_control.h b/src/core/ext/transport/chttp2/transport/flow_control.h
index a55ab82efb4..42c5986fd93 100644
--- a/src/core/ext/transport/chttp2/transport/flow_control.h
+++ b/src/core/ext/transport/chttp2/transport/flow_control.h
@@ -221,7 +221,7 @@ class TransportFlowControlDisabled final : public TransportFlowControlBase {
 class TransportFlowControl final : public TransportFlowControlBase {
  public:
   TransportFlowControl(const grpc_chttp2_transport* t, bool enable_bdp_probe);
-  ~TransportFlowControl() {}
+  ~TransportFlowControl() override {}
 
   bool flow_control_enabled() const override { return true; }
 
@@ -409,7 +409,7 @@ class StreamFlowControlDisabled : public StreamFlowControlBase {
 class StreamFlowControl final : public StreamFlowControlBase {
  public:
   StreamFlowControl(TransportFlowControl* tfc, const grpc_chttp2_stream* s);
-  ~StreamFlowControl() {
+  ~StreamFlowControl() override {
     tfc_->PreUpdateAnnouncedWindowOverIncomingWindow(announced_window_delta_);
   }
 
diff --git a/src/core/ext/xds/xds_client.h b/src/core/ext/xds/xds_client.h
index 9e222fbb536..eaa03da0a5e 100644
--- a/src/core/ext/xds/xds_client.h
+++ b/src/core/ext/xds/xds_client.h
@@ -86,7 +86,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
 
   // Callers should not instantiate directly.  Use GetOrCreate() instead.
   explicit XdsClient(grpc_error** error);
-  ~XdsClient();
+  ~XdsClient() override;
 
   grpc_pollset_set* interested_parties() const { return interested_parties_; }
 
@@ -199,7 +199,7 @@ class XdsClient : public DualRefCounted<XdsClient> {
 
     ChannelState(WeakRefCountedPtr<XdsClient> xds_client,
                  grpc_channel* channel);
-    ~ChannelState();
+    ~ChannelState() override;
 
     void Orphan() override;
 
diff --git a/src/core/ext/xds/xds_client_stats.h b/src/core/ext/xds/xds_client_stats.h
index 1906f08db2d..523ef111efc 100644
--- a/src/core/ext/xds/xds_client_stats.h
+++ b/src/core/ext/xds/xds_client_stats.h
@@ -131,7 +131,7 @@ class XdsClusterDropStats : public RefCounted<XdsClusterDropStats> {
                       absl::string_view lrs_server_name,
                       absl::string_view cluster_name,
                       absl::string_view eds_service_name);
-  ~XdsClusterDropStats();
+  ~XdsClusterDropStats() override;
 
   // Returns a snapshot of this instance and resets all the counters.
   Snapshot GetSnapshotAndReset();
@@ -206,7 +206,7 @@ class XdsClusterLocalityStats : public RefCounted<XdsClusterLocalityStats> {
                           absl::string_view cluster_name,
                           absl::string_view eds_service_name,
                           RefCountedPtr<XdsLocalityName> name);
-  ~XdsClusterLocalityStats();
+  ~XdsClusterLocalityStats() override;
 
   // Returns a snapshot of this instance and resets all the counters.
   Snapshot GetSnapshotAndReset();
diff --git a/src/core/lib/channel/channelz.h b/src/core/lib/channel/channelz.h
index d11a3227727..f39ad49d64e 100644
--- a/src/core/lib/channel/channelz.h
+++ b/src/core/lib/channel/channelz.h
@@ -87,7 +87,7 @@ class BaseNode : public RefCounted<BaseNode> {
   BaseNode(EntityType type, std::string name);
 
  public:
-  virtual ~BaseNode();
+  ~BaseNode() override;
 
   // All children must implement this function.
   virtual Json RenderJson() = 0;
diff --git a/src/core/lib/channel/handshaker.h b/src/core/lib/channel/handshaker.h
index 10b0631968f..541f38ed9dd 100644
--- a/src/core/lib/channel/handshaker.h
+++ b/src/core/lib/channel/handshaker.h
@@ -77,7 +77,7 @@ struct HandshakerArgs {
 
 class Handshaker : public RefCounted<Handshaker> {
  public:
-  virtual ~Handshaker() = default;
+  ~Handshaker() override = default;
   virtual void Shutdown(grpc_error* why) = 0;
   virtual void DoHandshake(grpc_tcp_server_acceptor* acceptor,
                            grpc_closure* on_handshake_done,
@@ -92,7 +92,7 @@ class Handshaker : public RefCounted<Handshaker> {
 class HandshakeManager : public RefCounted<HandshakeManager> {
  public:
   HandshakeManager();
-  ~HandshakeManager();
+  ~HandshakeManager() override;
 
   /// Add \a mgr to the server side list of all pending handshake managers, the
   /// list starts with \a *head.
diff --git a/src/core/lib/gprpp/dual_ref_counted.h b/src/core/lib/gprpp/dual_ref_counted.h
index 25d8625bf64..91469eaf051 100644
--- a/src/core/lib/gprpp/dual_ref_counted.h
+++ b/src/core/lib/gprpp/dual_ref_counted.h
@@ -51,7 +51,7 @@ namespace grpc_core {
 template <typename Child>
 class DualRefCounted : public Orphanable {
  public:
-  virtual ~DualRefCounted() = default;
+  ~DualRefCounted() override = default;
 
   RefCountedPtr<Child> Ref() GRPC_MUST_USE_RESULT {
     IncrementRefCount();
diff --git a/src/core/lib/gprpp/orphanable.h b/src/core/lib/gprpp/orphanable.h
index 4336538ac0b..2a95b9df13b 100644
--- a/src/core/lib/gprpp/orphanable.h
+++ b/src/core/lib/gprpp/orphanable.h
@@ -88,7 +88,7 @@ class InternallyRefCounted : public Orphanable {
   explicit InternallyRefCounted(const char* trace = nullptr,
                                 intptr_t initial_refcount = 1)
       : refs_(initial_refcount, trace) {}
-  virtual ~InternallyRefCounted() = default;
+  ~InternallyRefCounted() override = default;
 
   RefCountedPtr<Child> Ref() GRPC_MUST_USE_RESULT {
     IncrementRefCount();
diff --git a/src/core/lib/iomgr/executor/mpmcqueue.h b/src/core/lib/iomgr/executor/mpmcqueue.h
index 474f40bbf87..2af56903bc8 100644
--- a/src/core/lib/iomgr/executor/mpmcqueue.h
+++ b/src/core/lib/iomgr/executor/mpmcqueue.h
@@ -55,22 +55,22 @@ class InfLenFIFOQueue : public MPMCQueueInterface {
 
   // Releases all resources held by the queue. The queue must be empty, and no
   // one waits on conditional variables.
-  ~InfLenFIFOQueue();
+  ~InfLenFIFOQueue() override;
 
   // Puts elem into queue immediately at the end of queue. Since the queue has
   // infinite length, this routine will never block and should never fail.
-  void Put(void* elem);
+  void Put(void* elem) override;
 
   // Removes the oldest element from the queue and returns it.
   // This routine will cause the thread to block if queue is currently empty.
   // Argument wait_time should be passed in when trace flag turning on (for
   // collecting stats info purpose.)
-  void* Get(gpr_timespec* wait_time = nullptr);
+  void* Get(gpr_timespec* wait_time = nullptr) override;
 
   // Returns number of elements in queue currently.
   // There might be concurrently add/remove on queue, so count might change
   // quickly.
-  int count() const { return count_.Load(MemoryOrder::RELAXED); }
+  int count() const override { return count_.Load(MemoryOrder::RELAXED); }
 
   struct Node {
     Node* next;  // Linking
diff --git a/src/core/lib/security/certificate_provider.h b/src/core/lib/security/certificate_provider.h
index 5a9cfee0b94..81f68f8e669 100644
--- a/src/core/lib/security/certificate_provider.h
+++ b/src/core/lib/security/certificate_provider.h
@@ -44,7 +44,7 @@ struct grpc_tls_certificate_provider
   grpc_tls_certificate_provider()
       : interested_parties_(grpc_pollset_set_create()) {}
 
-  virtual ~grpc_tls_certificate_provider() {
+  ~grpc_tls_certificate_provider() override {
     grpc_pollset_set_destroy(interested_parties_);
   }
 
diff --git a/src/core/lib/security/credentials/credentials.h b/src/core/lib/security/credentials/credentials.h
index 1cc6e2d65f5..61e56e58144 100644
--- a/src/core/lib/security/credentials/credentials.h
+++ b/src/core/lib/security/credentials/credentials.h
@@ -102,7 +102,7 @@ struct grpc_channel_credentials
     : grpc_core::RefCounted<grpc_channel_credentials> {
  public:
   explicit grpc_channel_credentials(const char* type) : type_(type) {}
-  virtual ~grpc_channel_credentials() = default;
+  ~grpc_channel_credentials() override = default;
 
   // Creates a security connector for the channel. May also create new channel
   // args for the channel to be used in place of the passed in const args if
@@ -177,7 +177,7 @@ struct grpc_call_credentials
       grpc_security_level min_security_level = GRPC_PRIVACY_AND_INTEGRITY)
       : type_(type), min_security_level_(min_security_level) {}
 
-  virtual ~grpc_call_credentials() = default;
+  ~grpc_call_credentials() override = default;
 
   // Returns true if completed synchronously, in which case \a error will
   // be set to indicate the result.  Otherwise, \a on_request_metadata will
@@ -225,7 +225,7 @@ struct grpc_server_credentials
  public:
   explicit grpc_server_credentials(const char* type) : type_(type) {}
 
-  virtual ~grpc_server_credentials() { DestroyProcessor(); }
+  ~grpc_server_credentials() override { DestroyProcessor(); }
 
   virtual grpc_core::RefCountedPtr<grpc_server_security_connector>
   create_security_connector() = 0;
diff --git a/src/core/lib/security/credentials/tls/grpc_tls_credentials_options.h b/src/core/lib/security/credentials/tls/grpc_tls_credentials_options.h
index fcbff78e235..ccda9784fdd 100644
--- a/src/core/lib/security/credentials/tls/grpc_tls_credentials_options.h
+++ b/src/core/lib/security/credentials/tls/grpc_tls_credentials_options.h
@@ -96,7 +96,7 @@ struct grpc_tls_credential_reload_config
       void (*cancel)(void* config_user_data,
                      grpc_tls_credential_reload_arg* arg),
       void (*destruct)(void* config_user_data));
-  ~grpc_tls_credential_reload_config();
+  ~grpc_tls_credential_reload_config() override;
 
   void* context() const { return context_; }
   void set_context(void* context) { context_ = context; }
@@ -172,7 +172,7 @@ struct grpc_tls_server_authorization_check_config
       void (*cancel)(void* config_user_data,
                      grpc_tls_server_authorization_check_arg* arg),
       void (*destruct)(void* config_user_data));
-  ~grpc_tls_server_authorization_check_config();
+  ~grpc_tls_server_authorization_check_config() override;
 
   void* context() const { return context_; }
   void set_context(void* context) { context_ = context; }
@@ -245,7 +245,7 @@ struct grpc_tls_server_authorization_check_config
 struct grpc_tls_credentials_options
     : public grpc_core::RefCounted<grpc_tls_credentials_options> {
  public:
-  ~grpc_tls_credentials_options() {
+  ~grpc_tls_credentials_options() override {
     if (key_materials_config_.get() != nullptr) {
       key_materials_config_.get()->Unref();
     }
diff --git a/src/core/lib/security/security_connector/security_connector.h b/src/core/lib/security/security_connector/security_connector.h
index c3e264f30f9..204b6957462 100644
--- a/src/core/lib/security/security_connector/security_connector.h
+++ b/src/core/lib/security/security_connector/security_connector.h
@@ -53,7 +53,7 @@ class grpc_security_connector
                 ? "security_connector_refcount"
                 : nullptr),
         url_scheme_(url_scheme) {}
-  virtual ~grpc_security_connector() = default;
+  ~grpc_security_connector() override = default;
 
   /* Check the peer. Callee takes ownership of the peer object.
      When done, sets *auth_context and invokes on_peer_checked. */
diff --git a/src/core/lib/security/transport/security_handshaker.cc b/src/core/lib/security/transport/security_handshaker.cc
index 4566657da72..5563d5bd6a4 100644
--- a/src/core/lib/security/transport/security_handshaker.cc
+++ b/src/core/lib/security/transport/security_handshaker.cc
@@ -499,7 +499,7 @@ class FailHandshaker : public Handshaker {
   }
 
  private:
-  virtual ~FailHandshaker() = default;
+  ~FailHandshaker() override = default;
 };
 
 //
diff --git a/src/core/lib/surface/server.cc b/src/core/lib/surface/server.cc
index c94551545d1..4c8395836b2 100644
--- a/src/core/lib/surface/server.cc
+++ b/src/core/lib/surface/server.cc
@@ -936,7 +936,7 @@ class Server::ChannelData::ConnectivityWatcher
     GRPC_CHANNEL_INTERNAL_REF(chand_->channel_, "connectivity");
   }
 
-  ~ConnectivityWatcher() {
+  ~ConnectivityWatcher() override {
     GRPC_CHANNEL_INTERNAL_UNREF(chand_->channel_, "connectivity");
   }
 
diff --git a/src/core/lib/surface/server.h b/src/core/lib/surface/server.h
index 3a13b6f404e..af8ddab8c99 100644
--- a/src/core/lib/surface/server.h
+++ b/src/core/lib/surface/server.h
@@ -71,7 +71,7 @@ class Server : public InternallyRefCounted<Server> {
   /// listening and initiate destruction of the listener.
   class ListenerInterface : public Orphanable {
    public:
-    virtual ~ListenerInterface() = default;
+    ~ListenerInterface() override = default;
 
     /// Starts listening. This listener may refer to the pollset object beyond
     /// this call, so it is a pointer rather than a reference.
@@ -88,7 +88,7 @@ class Server : public InternallyRefCounted<Server> {
   };
 
   explicit Server(const grpc_channel_args* args);
-  ~Server();
+  ~Server() override;
 
   void Orphan() override;
 
diff --git a/src/core/lib/transport/byte_stream.h b/src/core/lib/transport/byte_stream.h
index ecb605ad9bb..e83fb626b32 100644
--- a/src/core/lib/transport/byte_stream.h
+++ b/src/core/lib/transport/byte_stream.h
@@ -40,7 +40,7 @@ namespace grpc_core {
 
 class ByteStream : public Orphanable {
  public:
-  virtual ~ByteStream() {}
+  ~ByteStream() override {}
 
   // Returns true if the bytes are available immediately (in which case
   // on_complete will not be called), or false if the bytes will be available
@@ -92,7 +92,7 @@ class SliceBufferByteStream : public ByteStream {
   // Removes all slices in slice_buffer, leaving it empty.
   SliceBufferByteStream(grpc_slice_buffer* slice_buffer, uint32_t flags);
 
-  ~SliceBufferByteStream();
+  ~SliceBufferByteStream() override;
 
   void Orphan() override;
 
@@ -126,7 +126,7 @@ class ByteStreamCache {
    public:
     explicit CachingByteStream(ByteStreamCache* cache);
 
-    ~CachingByteStream();
+    ~CachingByteStream() override;
 
     void Orphan() override;
 
diff --git a/src/core/lib/transport/connectivity_state.h b/src/core/lib/transport/connectivity_state.h
index 6b1d68cf8ef..cad34c27003 100644
--- a/src/core/lib/transport/connectivity_state.h
+++ b/src/core/lib/transport/connectivity_state.h
@@ -48,7 +48,7 @@ const char* ConnectivityStateName(grpc_connectivity_state state);
 class ConnectivityStateWatcherInterface
     : public InternallyRefCounted<ConnectivityStateWatcherInterface> {
  public:
-  virtual ~ConnectivityStateWatcherInterface() = default;
+  ~ConnectivityStateWatcherInterface() override = default;
 
   // Notifies the watcher that the state has changed to new_state.
   virtual void Notify(grpc_connectivity_state new_state,
@@ -63,12 +63,12 @@ class ConnectivityStateWatcherInterface
 class AsyncConnectivityStateWatcherInterface
     : public ConnectivityStateWatcherInterface {
  public:
-  virtual ~AsyncConnectivityStateWatcherInterface() = default;
+  ~AsyncConnectivityStateWatcherInterface() override = default;
 
   // Schedules a closure on the ExecCtx to invoke
   // OnConnectivityStateChange() asynchronously.
   void Notify(grpc_connectivity_state new_state,
-              const absl::Status& status) override final;
+              const absl::Status& status) final;
 
  protected:
   class Notifier;
diff --git a/src/core/tsi/ssl/session_cache/ssl_session_cache.h b/src/core/tsi/ssl/session_cache/ssl_session_cache.h
index 5d91af7b18d..e805ed6b14e 100644
--- a/src/core/tsi/ssl/session_cache/ssl_session_cache.h
+++ b/src/core/tsi/ssl/session_cache/ssl_session_cache.h
@@ -53,7 +53,7 @@ class SslSessionLRUCache : public grpc_core::RefCounted<SslSessionLRUCache> {
 
   // Use Create function instead of using this directly.
   explicit SslSessionLRUCache(size_t capacity);
-  ~SslSessionLRUCache();
+  ~SslSessionLRUCache() override;
 
   // Not copyable nor movable.
   SslSessionLRUCache(const SslSessionLRUCache&) = delete;
diff --git a/src/cpp/client/secure_credentials.h b/src/cpp/client/secure_credentials.h
index 0c47701ec3c..f9fa5e4a67b 100644
--- a/src/cpp/client/secure_credentials.h
+++ b/src/cpp/client/secure_credentials.h
@@ -37,7 +37,7 @@ class Channel;
 class SecureChannelCredentials final : public ChannelCredentials {
  public:
   explicit SecureChannelCredentials(grpc_channel_credentials* c_creds);
-  ~SecureChannelCredentials() {
+  ~SecureChannelCredentials() override {
     if (c_creds_ != nullptr) c_creds_->Unref();
   }
   grpc_channel_credentials* GetRawCreds() { return c_creds_; }
@@ -59,7 +59,7 @@ class SecureChannelCredentials final : public ChannelCredentials {
 class SecureCallCredentials final : public CallCredentials {
  public:
   explicit SecureCallCredentials(grpc_call_credentials* c_creds);
-  ~SecureCallCredentials() {
+  ~SecureCallCredentials() override {
     if (c_creds_ != nullptr) c_creds_->Unref();
   }
   grpc_call_credentials* GetRawCreds() { return c_creds_; }
diff --git a/src/cpp/common/alarm.cc b/src/cpp/common/alarm.cc
index a2612874b20..3926e4ad7db 100644
--- a/src/cpp/common/alarm.cc
+++ b/src/cpp/common/alarm.cc
@@ -41,7 +41,7 @@ class AlarmImpl : public ::grpc::internal::CompletionQueueTag {
     gpr_ref_init(&refs_, 1);
     grpc_timer_init_unset(&timer_);
   }
-  ~AlarmImpl() {}
+  ~AlarmImpl() override {}
   bool FinalizeResult(void** tag, bool* /*status*/) override {
     *tag = tag_;
     Unref();
diff --git a/src/cpp/common/secure_auth_context.h b/src/cpp/common/secure_auth_context.h
index 3375237c34b..83c222749b8 100644
--- a/src/cpp/common/secure_auth_context.h
+++ b/src/cpp/common/secure_auth_context.h
@@ -49,7 +49,7 @@ class SecureAuthContext final : public AuthContext {
   void AddProperty(const std::string& key,
                    const grpc::string_ref& value) override;
 
-  virtual bool SetPeerIdentityPropertyName(const std::string& name) override;
+  bool SetPeerIdentityPropertyName(const std::string& name) override;
 
  private:
   grpc_core::RefCountedPtr<grpc_auth_context> ctx_;
diff --git a/src/cpp/server/channel_argument_option.cc b/src/cpp/server/channel_argument_option.cc
index a8e5e52a770..680b0ee0484 100644
--- a/src/cpp/server/channel_argument_option.cc
+++ b/src/cpp/server/channel_argument_option.cc
@@ -27,10 +27,10 @@ std::unique_ptr<ServerBuilderOption> MakeChannelArgumentOption(
     StringOption(const std::string& name, const std::string& value)
         : name_(name), value_(value) {}
 
-    virtual void UpdateArguments(ChannelArguments* args) override {
+    void UpdateArguments(ChannelArguments* args) override {
       args->SetString(name_, value_);
     }
-    virtual void UpdatePlugins(
+    void UpdatePlugins(
         std::vector<std::unique_ptr<ServerBuilderPlugin>>* /*plugins*/)
         override {}
 
@@ -48,10 +48,10 @@ std::unique_ptr<ServerBuilderOption> MakeChannelArgumentOption(
     IntOption(const std::string& name, int value)
         : name_(name), value_(value) {}
 
-    virtual void UpdateArguments(ChannelArguments* args) override {
+    void UpdateArguments(ChannelArguments* args) override {
       args->SetInt(name_, value_);
     }
-    virtual void UpdatePlugins(
+    void UpdatePlugins(
         std::vector<std::unique_ptr<ServerBuilderPlugin>>* /*plugins*/)
         override {}
 
diff --git a/src/cpp/server/dynamic_thread_pool.h b/src/cpp/server/dynamic_thread_pool.h
index 6f9f943bc38..3bc7b677bad 100644
--- a/src/cpp/server/dynamic_thread_pool.h
+++ b/src/cpp/server/dynamic_thread_pool.h
@@ -34,7 +34,7 @@ namespace grpc {
 class DynamicThreadPool final : public ThreadPoolInterface {
  public:
   explicit DynamicThreadPool(int reserve_threads);
-  ~DynamicThreadPool();
+  ~DynamicThreadPool() override;
 
   void Add(const std::function<void()>& callback) override;
 
diff --git a/src/cpp/server/health/default_health_check_service.h b/src/cpp/server/health/default_health_check_service.h
index 0d4b60ec0da..e62189bd08e 100644
--- a/src/cpp/server/health/default_health_check_service.h
+++ b/src/cpp/server/health/default_health_check_service.h
@@ -56,7 +56,7 @@ class DefaultHealthCheckService final : public HealthCheckServiceInterface {
     HealthCheckServiceImpl(DefaultHealthCheckService* database,
                            std::unique_ptr<ServerCompletionQueue> cq);
 
-    ~HealthCheckServiceImpl();
+    ~HealthCheckServiceImpl() override;
 
     void StartServingThread();
 
diff --git a/src/cpp/server/load_reporter/load_reporter_async_service_impl.h b/src/cpp/server/load_reporter/load_reporter_async_service_impl.h
index 969e20f6245..d8452955fd3 100644
--- a/src/cpp/server/load_reporter/load_reporter_async_service_impl.h
+++ b/src/cpp/server/load_reporter/load_reporter_async_service_impl.h
@@ -41,7 +41,7 @@ class LoadReporterAsyncServiceImpl
  public:
   explicit LoadReporterAsyncServiceImpl(
       std::unique_ptr<ServerCompletionQueue> cq);
-  ~LoadReporterAsyncServiceImpl();
+  ~LoadReporterAsyncServiceImpl() override;
 
   // Starts the working thread.
   void StartThread();
diff --git a/src/cpp/server/server_cc.cc b/src/cpp/server/server_cc.cc
index 361a087a57f..6bc0b201f61 100644
--- a/src/cpp/server/server_cc.cc
+++ b/src/cpp/server/server_cc.cc
@@ -81,12 +81,16 @@ void InitGlobalCallbacks() {
 
 class ShutdownTag : public internal::CompletionQueueTag {
  public:
-  bool FinalizeResult(void** /*tag*/, bool* /*status*/) { return false; }
+  bool FinalizeResult(void** /*tag*/, bool* /*status*/) override {
+    return false;
+  }
 };
 
 class DummyTag : public internal::CompletionQueueTag {
  public:
-  bool FinalizeResult(void** /*tag*/, bool* /*status*/) { return true; }
+  bool FinalizeResult(void** /*tag*/, bool* /*status*/) override {
+    return true;
+  }
 };
 
 class UnimplementedAsyncRequestContext {
@@ -310,7 +314,7 @@ class Server::UnimplementedAsyncResponse final
           grpc::internal::CallOpServerSendStatus> {
  public:
   UnimplementedAsyncResponse(UnimplementedAsyncRequest* request);
-  ~UnimplementedAsyncResponse() { delete request_; }
+  ~UnimplementedAsyncResponse() override { delete request_; }
 
   bool FinalizeResult(void** tag, bool* status) override {
     if (grpc::internal::CallOpSet<
@@ -343,7 +347,7 @@ class Server::SyncRequest final : public grpc::internal::CompletionQueueTag {
     grpc_metadata_array_init(&request_metadata_);
   }
 
-  ~SyncRequest() {
+  ~SyncRequest() override {
     if (call_details_) {
       delete call_details_;
     }
@@ -567,7 +571,7 @@ class Server::CallbackRequest final
     data->details = call_details_;
   }
 
-  ~CallbackRequest() {
+  ~CallbackRequest() override {
     delete call_details_;
     grpc_metadata_array_destroy(&request_metadata_);
     if (has_request_payload_ && request_payload_) {
diff --git a/src/cpp/server/server_context.cc b/src/cpp/server/server_context.cc
index 9cd6b2a4f6a..f3cb004f65f 100644
--- a/src/cpp/server/server_context.cc
+++ b/src/cpp/server/server_context.cc
@@ -62,7 +62,7 @@ class ServerContextBase::CompletionOp final
   CompletionOp(CompletionOp&&) = delete;
   CompletionOp& operator=(CompletionOp&&) = delete;
 
-  ~CompletionOp() {
+  ~CompletionOp() override {
     if (call_.server_rpc_info()) {
       call_.server_rpc_info()->Unref();
     }
diff --git a/test/core/gprpp/dual_ref_counted_test.cc b/test/core/gprpp/dual_ref_counted_test.cc
index 3dd39ff1e4f..53fe0882d3b 100644
--- a/test/core/gprpp/dual_ref_counted_test.cc
+++ b/test/core/gprpp/dual_ref_counted_test.cc
@@ -30,7 +30,7 @@ namespace {
 class Foo : public DualRefCounted<Foo> {
  public:
   Foo() = default;
-  ~Foo() { GPR_ASSERT(shutting_down_); }
+  ~Foo() override { GPR_ASSERT(shutting_down_); }
 
   void Orphan() override { shutting_down_ = true; }
 
@@ -75,7 +75,7 @@ TEST(DualRefCounted, RefIfNonZero) {
 class FooWithTracing : public DualRefCounted<FooWithTracing> {
  public:
   FooWithTracing() : DualRefCounted("FooWithTracing") {}
-  ~FooWithTracing() { GPR_ASSERT(shutting_down_); }
+  ~FooWithTracing() override { GPR_ASSERT(shutting_down_); }
 
   void Orphan() override { shutting_down_ = true; }
 
diff --git a/test/core/gprpp/manual_constructor_test.cc b/test/core/gprpp/manual_constructor_test.cc
index 5f41920391a..828f2f89aa9 100644
--- a/test/core/gprpp/manual_constructor_test.cc
+++ b/test/core/gprpp/manual_constructor_test.cc
@@ -39,7 +39,7 @@ class A {
 class B : public A {
  public:
   B() {}
-  ~B() {}
+  ~B() override {}
   const char* foo() override { return "B_foo"; }
   char get_junk() { return junk[0]; }
 
@@ -50,8 +50,8 @@ class B : public A {
 class C : public B {
  public:
   C() {}
-  ~C() {}
-  virtual const char* bar() { return "C_bar"; }
+  ~C() override {}
+  const char* bar() override { return "C_bar"; }
   char get_more_junk() { return more_junk[0]; }
 
  private:
@@ -60,7 +60,7 @@ class C : public B {
 
 class D : public A {
  public:
-  virtual const char* bar() { return "D_bar"; }
+  const char* bar() override { return "D_bar"; }
 };
 
 static void basic_test() {
diff --git a/test/core/gprpp/ref_counted_ptr_test.cc b/test/core/gprpp/ref_counted_ptr_test.cc
index a32957aaf20..bf202970141 100644
--- a/test/core/gprpp/ref_counted_ptr_test.cc
+++ b/test/core/gprpp/ref_counted_ptr_test.cc
@@ -266,7 +266,7 @@ class Bar : public DualRefCounted<Bar> {
 
   explicit Bar(int value) : value_(value) {}
 
-  ~Bar() { GPR_ASSERT(shutting_down_); }
+  ~Bar() override { GPR_ASSERT(shutting_down_); }
 
   void Orphan() override { shutting_down_ = true; }
 
@@ -422,7 +422,7 @@ class BarWithTracing : public DualRefCounted<BarWithTracing> {
  public:
   BarWithTracing() : DualRefCounted("BarWithTracing") {}
 
-  ~BarWithTracing() { GPR_ASSERT(shutting_down_); }
+  ~BarWithTracing() override { GPR_ASSERT(shutting_down_); }
 
   void Orphan() override { shutting_down_ = true; }
 
@@ -442,7 +442,7 @@ class WeakBaseClass : public DualRefCounted<WeakBaseClass> {
  public:
   WeakBaseClass() {}
 
-  ~WeakBaseClass() { GPR_ASSERT(shutting_down_); }
+  ~WeakBaseClass() override { GPR_ASSERT(shutting_down_); }
 
   void Orphan() override { shutting_down_ = true; }
 
diff --git a/test/core/handshake/readahead_handshaker_server_ssl.cc b/test/core/handshake/readahead_handshaker_server_ssl.cc
index 36f79e8193f..c1468503e7b 100644
--- a/test/core/handshake/readahead_handshaker_server_ssl.cc
+++ b/test/core/handshake/readahead_handshaker_server_ssl.cc
@@ -53,7 +53,7 @@ namespace grpc_core {
 
 class ReadAheadHandshaker : public Handshaker {
  public:
-  virtual ~ReadAheadHandshaker() {}
+  ~ReadAheadHandshaker() override {}
   const char* name() const override { return "read_ahead"; }
   void Shutdown(grpc_error* /*why*/) override {}
   void DoHandshake(grpc_tcp_server_acceptor* /*acceptor*/,
diff --git a/test/core/security/credentials_test.cc b/test/core/security/credentials_test.cc
index a3f91b21dad..308b6fd0f35 100644
--- a/test/core/security/credentials_test.cc
+++ b/test/core/security/credentials_test.cc
@@ -1579,19 +1579,19 @@ struct fake_call_creds : public grpc_call_credentials {
     grpc_slice_unref(value);
   }
 
-  ~fake_call_creds() { GRPC_MDELEM_UNREF(dummy_md_); }
+  ~fake_call_creds() override { GRPC_MDELEM_UNREF(dummy_md_); }
 
   bool get_request_metadata(grpc_polling_entity* pollent,
                             grpc_auth_metadata_context context,
                             grpc_credentials_mdelem_array* md_array,
                             grpc_closure* on_request_metadata,
-                            grpc_error** error) {
+                            grpc_error** error) override {
     grpc_credentials_mdelem_array_add(md_array, dummy_md_);
     return true;
   }
 
   void cancel_get_request_metadata(grpc_credentials_mdelem_array* md_array,
-                                   grpc_error* error) {}
+                                   grpc_error* error) override {}
 
  private:
   grpc_mdelem dummy_md_;
@@ -2001,9 +2001,10 @@ class TestExternalAccountCredentials final
       : ExternalAccountCredentials(std::move(options), std::move(scopes)) {}
 
  protected:
-  void RetrieveSubjectToken(const HTTPRequestContext* ctx,
-                            const ExternalAccountCredentialsOptions& options,
-                            std::function<void(std::string, grpc_error*)> cb) {
+  void RetrieveSubjectToken(
+      const HTTPRequestContext* ctx,
+      const ExternalAccountCredentialsOptions& options,
+      std::function<void(std::string, grpc_error*)> cb) override {
     cb("test_subject_token", GRPC_ERROR_NONE);
   }
 };
diff --git a/test/core/security/grpc_tls_certificate_distributor_test.cc b/test/core/security/grpc_tls_certificate_distributor_test.cc
index 83456eafa3a..6c67770bffe 100644
--- a/test/core/security/grpc_tls_certificate_distributor_test.cc
+++ b/test/core/security/grpc_tls_certificate_distributor_test.cc
@@ -126,7 +126,7 @@ class GrpcTlsCertificateDistributorTest : public ::testing::Test {
     }
 
     // dtor sets state->watcher to nullptr.
-    ~TlsCertificatesTestWatcher() { state_->watcher = nullptr; }
+    ~TlsCertificatesTestWatcher() override { state_->watcher = nullptr; }
 
     void OnCertificatesChanged(
         absl::optional<absl::string_view> root_certs,
diff --git a/test/core/transport/connectivity_state_test.cc b/test/core/transport/connectivity_state_test.cc
index 9caff9db9b8..21ea0114be7 100644
--- a/test/core/transport/connectivity_state_test.cc
+++ b/test/core/transport/connectivity_state_test.cc
@@ -49,7 +49,7 @@ class Watcher : public ConnectivityStateWatcherInterface {
         status_(status),
         destroyed_(destroyed) {}
 
-  ~Watcher() {
+  ~Watcher() override {
     if (destroyed_ != nullptr) *destroyed_ = true;
   }
 
diff --git a/test/core/util/fuzzer_corpus_test.cc b/test/core/util/fuzzer_corpus_test.cc
index 70dadcbb5dc..25b6a24a7c0 100644
--- a/test/core/util/fuzzer_corpus_test.cc
+++ b/test/core/util/fuzzer_corpus_test.cc
@@ -73,9 +73,10 @@ TEST_P(FuzzerCorpusTest, RunOneExample) {
 class ExampleGenerator
     : public ::testing::internal::ParamGeneratorInterface<std::string> {
  public:
-  virtual ::testing::internal::ParamIteratorInterface<std::string>* Begin()
-      const;
-  virtual ::testing::internal::ParamIteratorInterface<std::string>* End() const;
+  ::testing::internal::ParamIteratorInterface<std::string>* Begin()
+      const override;
+  ::testing::internal::ParamIteratorInterface<std::string>* End()
+      const override;
 
  private:
   void Materialize() const {
@@ -124,13 +125,13 @@ class ExampleIterator
                   std::vector<std::string>::const_iterator begin)
       : base_(base_), begin_(begin), current_(begin) {}
 
-  virtual const ExampleGenerator* BaseGenerator() const { return &base_; }
+  const ExampleGenerator* BaseGenerator() const override { return &base_; }
 
-  virtual void Advance() { current_++; }
-  virtual ExampleIterator* Clone() const { return new ExampleIterator(*this); }
-  virtual const std::string* Current() const { return &*current_; }
+  void Advance() override { current_++; }
+  ExampleIterator* Clone() const override { return new ExampleIterator(*this); }
+  const std::string* Current() const override { return &*current_; }
 
-  virtual bool Equals(const ParamIteratorInterface<std::string>& other) const {
+  bool Equals(const ParamIteratorInterface<std::string>& other) const override {
     return &base_ == other.BaseGenerator() &&
            current_ == dynamic_cast<const ExampleIterator*>(&other)->current_;
   }
diff --git a/test/cpp/end2end/client_interceptors_end2end_test.cc b/test/cpp/end2end/client_interceptors_end2end_test.cc
index 58d9c2a8bb2..baf93e023d3 100644
--- a/test/cpp/end2end/client_interceptors_end2end_test.cc
+++ b/test/cpp/end2end/client_interceptors_end2end_test.cc
@@ -64,7 +64,7 @@ class HijackingInterceptor : public experimental::Interceptor {
     EXPECT_EQ(info->type(), experimental::ClientRpcInfo::Type::UNARY);
   }
 
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     bool hijack = false;
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
@@ -155,7 +155,7 @@ class HijackingInterceptor : public experimental::Interceptor {
 class HijackingInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* info) override {
     return new HijackingInterceptor(info);
   }
@@ -169,7 +169,7 @@ class HijackingInterceptorMakesAnotherCall : public experimental::Interceptor {
     EXPECT_EQ(strcmp("/grpc.testing.EchoTestService/Echo", info->method()), 0);
   }
 
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
       auto* map = methods->GetSendInitialMetadata();
@@ -277,7 +277,7 @@ class HijackingInterceptorMakesAnotherCall : public experimental::Interceptor {
 class HijackingInterceptorMakesAnotherCallFactory
     : public experimental::ClientInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* info) override {
     return new HijackingInterceptorMakesAnotherCall(info);
   }
@@ -289,7 +289,7 @@ class BidiStreamingRpcHijackingInterceptor : public experimental::Interceptor {
     info_ = info;
   }
 
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     bool hijack = false;
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
@@ -358,7 +358,7 @@ class ClientStreamingRpcHijackingInterceptor
   ClientStreamingRpcHijackingInterceptor(experimental::ClientRpcInfo* info) {
     info_ = info;
   }
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     bool hijack = false;
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
@@ -400,7 +400,7 @@ bool ClientStreamingRpcHijackingInterceptor::got_failed_send_ = false;
 class ClientStreamingRpcHijackingInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* info) override {
     return new ClientStreamingRpcHijackingInterceptor(info);
   }
@@ -414,7 +414,7 @@ class ServerStreamingRpcHijackingInterceptor
     got_failed_message_ = false;
   }
 
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     bool hijack = false;
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
@@ -498,7 +498,7 @@ bool ServerStreamingRpcHijackingInterceptor::got_failed_message_ = false;
 class ServerStreamingRpcHijackingInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* info) override {
     return new ServerStreamingRpcHijackingInterceptor(info);
   }
@@ -507,7 +507,7 @@ class ServerStreamingRpcHijackingInterceptorFactory
 class BidiStreamingRpcHijackingInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* info) override {
     return new BidiStreamingRpcHijackingInterceptor(info);
   }
@@ -528,7 +528,7 @@ class LoggingInterceptor : public experimental::Interceptor {
     post_recv_status_ = false;
   }
 
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
       auto* map = methods->GetSendInitialMetadata();
@@ -677,7 +677,7 @@ bool LoggingInterceptor::post_recv_status_;
 class LoggingInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* info) override {
     return new LoggingInterceptor(info);
   }
@@ -717,7 +717,9 @@ class ParameterizedClientInterceptorsEnd2endTest
     server_ = builder.BuildAndStart();
   }
 
-  ~ParameterizedClientInterceptorsEnd2endTest() { server_->Shutdown(); }
+  ~ParameterizedClientInterceptorsEnd2endTest() override {
+    server_->Shutdown();
+  }
 
   void SendRPC(const std::shared_ptr<Channel>& channel) {
     switch (GetParam().type()) {
@@ -791,7 +793,7 @@ class ClientInterceptorsEnd2endTest
     server_ = builder.BuildAndStart();
   }
 
-  ~ClientInterceptorsEnd2endTest() { server_->Shutdown(); }
+  ~ClientInterceptorsEnd2endTest() override { server_->Shutdown(); }
 
   std::string server_address_;
   TestServiceImpl service_;
@@ -890,7 +892,7 @@ class ClientInterceptorsCallbackEnd2endTest : public ::testing::Test {
     server_ = builder.BuildAndStart();
   }
 
-  ~ClientInterceptorsCallbackEnd2endTest() { server_->Shutdown(); }
+  ~ClientInterceptorsCallbackEnd2endTest() override { server_->Shutdown(); }
 
   std::string server_address_;
   TestServiceImpl service_;
@@ -953,7 +955,7 @@ class ClientInterceptorsStreamingEnd2endTest : public ::testing::Test {
     server_ = builder.BuildAndStart();
   }
 
-  ~ClientInterceptorsStreamingEnd2endTest() { server_->Shutdown(); }
+  ~ClientInterceptorsStreamingEnd2endTest() override { server_->Shutdown(); }
 
   std::string server_address_;
   EchoTestServiceStreamingImpl service_;
@@ -1103,7 +1105,7 @@ class ClientGlobalInterceptorEnd2endTest : public ::testing::Test {
     server_ = builder.BuildAndStart();
   }
 
-  ~ClientGlobalInterceptorEnd2endTest() { server_->Shutdown(); }
+  ~ClientGlobalInterceptorEnd2endTest() override { server_->Shutdown(); }
 
   std::string server_address_;
   TestServiceImpl service_;
diff --git a/test/cpp/end2end/delegating_channel_test.cc b/test/cpp/end2end/delegating_channel_test.cc
index e3e975bbfc8..9b371e29a29 100644
--- a/test/cpp/end2end/delegating_channel_test.cc
+++ b/test/cpp/end2end/delegating_channel_test.cc
@@ -64,7 +64,7 @@ class DelegatingChannelTest : public ::testing::Test {
     server_ = builder.BuildAndStart();
   }
 
-  ~DelegatingChannelTest() { server_->Shutdown(); }
+  ~DelegatingChannelTest() override { server_->Shutdown(); }
 
   std::string server_address_;
   TestServiceImpl service_;
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index f157d20cc6f..c7fbd852861 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -1858,7 +1858,7 @@ class CredentialsInterceptor : public experimental::Interceptor {
  public:
   CredentialsInterceptor(experimental::ClientRpcInfo* info) : info_(info) {}
 
-  void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
       std::shared_ptr<CallCredentials> creds =
@@ -1875,7 +1875,7 @@ class CredentialsInterceptor : public experimental::Interceptor {
 class CredentialsInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface {
   CredentialsInterceptor* CreateClientInterceptor(
-      experimental::ClientRpcInfo* info) {
+      experimental::ClientRpcInfo* info) override {
     return new CredentialsInterceptor(info);
   }
 };
@@ -2245,7 +2245,7 @@ class ResourceQuotaEnd2endTest : public End2endTest {
   ResourceQuotaEnd2endTest()
       : server_resource_quota_("server_resource_quota") {}
 
-  virtual void ConfigureServerBuilder(ServerBuilder* builder) override {
+  void ConfigureServerBuilder(ServerBuilder* builder) override {
     builder->SetResourceQuota(server_resource_quota_);
   }
 
diff --git a/test/cpp/end2end/filter_end2end_test.cc b/test/cpp/end2end/filter_end2end_test.cc
index 062a47a8bef..56ea3438731 100644
--- a/test/cpp/end2end/filter_end2end_test.cc
+++ b/test/cpp/end2end/filter_end2end_test.cc
@@ -101,7 +101,7 @@ int GetCallCounterValue() {
 class ChannelDataImpl : public ChannelData {
  public:
   grpc_error* Init(grpc_channel_element* /*elem*/,
-                   grpc_channel_element_args* /*args*/) {
+                   grpc_channel_element_args* /*args*/) override {
     IncrementConnectionCounter();
     return GRPC_ERROR_NONE;
   }
diff --git a/test/cpp/end2end/interceptors_util.h b/test/cpp/end2end/interceptors_util.h
index 4eafcea2670..01009cdc93f 100644
--- a/test/cpp/end2end/interceptors_util.h
+++ b/test/cpp/end2end/interceptors_util.h
@@ -33,7 +33,7 @@ class DummyInterceptor : public experimental::Interceptor {
  public:
   DummyInterceptor() {}
 
-  virtual void Intercept(experimental::InterceptorBatchMethods* methods) {
+  void Intercept(experimental::InterceptorBatchMethods* methods) override {
     if (methods->QueryInterceptionHookPoint(
             experimental::InterceptionHookPoints::PRE_SEND_INITIAL_METADATA)) {
       num_times_run_++;
@@ -71,12 +71,12 @@ class DummyInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface,
       public experimental::ServerInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* /*info*/) override {
     return new DummyInterceptor();
   }
 
-  virtual experimental::Interceptor* CreateServerInterceptor(
+  experimental::Interceptor* CreateServerInterceptor(
       experimental::ServerRpcInfo* /*info*/) override {
     return new DummyInterceptor();
   }
@@ -87,12 +87,12 @@ class NullInterceptorFactory
     : public experimental::ClientInterceptorFactoryInterface,
       public experimental::ServerInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateClientInterceptor(
+  experimental::Interceptor* CreateClientInterceptor(
       experimental::ClientRpcInfo* /*info*/) override {
     return nullptr;
   }
 
-  virtual experimental::Interceptor* CreateServerInterceptor(
+  experimental::Interceptor* CreateServerInterceptor(
       experimental::ServerRpcInfo* /*info*/) override {
     return nullptr;
   }
diff --git a/test/cpp/end2end/message_allocator_end2end_test.cc b/test/cpp/end2end/message_allocator_end2end_test.cc
index 2c022940b29..c2cd0c19f7f 100644
--- a/test/cpp/end2end/message_allocator_end2end_test.cc
+++ b/test/cpp/end2end/message_allocator_end2end_test.cc
@@ -127,7 +127,7 @@ class MessageAllocatorEnd2endTestBase
     }
   }
 
-  ~MessageAllocatorEnd2endTestBase() = default;
+  ~MessageAllocatorEnd2endTestBase() override = default;
 
   void CreateServer(
       experimental::MessageAllocator<EchoRequest, EchoResponse>* allocator) {
diff --git a/test/cpp/end2end/server_interceptors_end2end_test.cc b/test/cpp/end2end/server_interceptors_end2end_test.cc
index 984651d9042..02488c8ac4b 100644
--- a/test/cpp/end2end/server_interceptors_end2end_test.cc
+++ b/test/cpp/end2end/server_interceptors_end2end_test.cc
@@ -140,7 +140,7 @@ class LoggingInterceptor : public experimental::Interceptor {
 class LoggingInterceptorFactory
     : public experimental::ServerInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateServerInterceptor(
+  experimental::Interceptor* CreateServerInterceptor(
       experimental::ServerRpcInfo* info) override {
     return new LoggingInterceptor(info);
   }
@@ -170,7 +170,7 @@ class SyncSendMessageTester : public experimental::Interceptor {
 class SyncSendMessageTesterFactory
     : public experimental::ServerInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateServerInterceptor(
+  experimental::Interceptor* CreateServerInterceptor(
       experimental::ServerRpcInfo* info) override {
     return new SyncSendMessageTester(info);
   }
@@ -205,7 +205,7 @@ class SyncSendMessageVerifier : public experimental::Interceptor {
 class SyncSendMessageVerifierFactory
     : public experimental::ServerInterceptorFactoryInterface {
  public:
-  virtual experimental::Interceptor* CreateServerInterceptor(
+  experimental::Interceptor* CreateServerInterceptor(
       experimental::ServerRpcInfo* info) override {
     return new SyncSendMessageVerifier(info);
   }
diff --git a/test/cpp/end2end/time_change_test.cc b/test/cpp/end2end/time_change_test.cc
index 066914310eb..3fc58c2fac5 100644
--- a/test/cpp/end2end/time_change_test.cc
+++ b/test/cpp/end2end/time_change_test.cc
@@ -148,14 +148,14 @@ class TimeChangeTest : public ::testing::Test {
 
   static void TearDownTestCase() { server_.reset(); }
 
-  void SetUp() {
+  void SetUp() override {
     channel_ =
         grpc::CreateChannel(server_address_, InsecureChannelCredentials());
     GPR_ASSERT(channel_);
     stub_ = grpc::testing::EchoTestService::NewStub(channel_);
   }
 
-  void TearDown() { reset_now_offset(); }
+  void TearDown() override { reset_now_offset(); }
 
   std::unique_ptr<grpc::testing::EchoTestService::Stub> CreateStub() {
     return grpc::testing::EchoTestService::NewStub(channel_);
diff --git a/test/cpp/ext/filters/census/stats_plugin_end2end_test.cc b/test/cpp/ext/filters/census/stats_plugin_end2end_test.cc
index d007971ed58..0e947c6c014 100644
--- a/test/cpp/ext/filters/census/stats_plugin_end2end_test.cc
+++ b/test/cpp/ext/filters/census/stats_plugin_end2end_test.cc
@@ -70,7 +70,7 @@ class StatsPluginEnd2EndTest : public ::testing::Test {
  protected:
   static void SetUpTestCase() { RegisterOpenCensusPlugin(); }
 
-  void SetUp() {
+  void SetUp() override {
     // Set up a synchronous server on a different thread to avoid the asynch
     // interface.
     ::grpc::ServerBuilder builder;
@@ -89,7 +89,7 @@ class StatsPluginEnd2EndTest : public ::testing::Test {
         server_address_, ::grpc::InsecureChannelCredentials()));
   }
 
-  void TearDown() {
+  void TearDown() override {
     server_->Shutdown();
     server_thread_.join();
   }
diff --git a/test/cpp/interop/interop_server.cc b/test/cpp/interop/interop_server.cc
index 153aec7c9c2..f7e3c8c0e9b 100644
--- a/test/cpp/interop/interop_server.cc
+++ b/test/cpp/interop/interop_server.cc
@@ -139,7 +139,7 @@ class TestServiceImpl : public TestService::Service {
  public:
   Status EmptyCall(ServerContext* context,
                    const grpc::testing::Empty* /*request*/,
-                   grpc::testing::Empty* /*response*/) {
+                   grpc::testing::Empty* /*response*/) override {
     MaybeEchoMetadata(context);
     return Status::OK;
   }
@@ -147,7 +147,7 @@ class TestServiceImpl : public TestService::Service {
   // Response contains current timestamp. We ignore everything in the request.
   Status CacheableUnaryCall(ServerContext* context,
                             const SimpleRequest* /*request*/,
-                            SimpleResponse* response) {
+                            SimpleResponse* response) override {
     gpr_timespec ts = gpr_now(GPR_CLOCK_PRECISE);
     std::string timestamp = std::to_string((long long unsigned)ts.tv_nsec);
     response->mutable_payload()->set_body(timestamp.c_str(), timestamp.size());
@@ -156,7 +156,7 @@ class TestServiceImpl : public TestService::Service {
   }
 
   Status UnaryCall(ServerContext* context, const SimpleRequest* request,
-                   SimpleResponse* response) {
+                   SimpleResponse* response) override {
     MaybeEchoMetadata(context);
     if (request->has_response_compressed()) {
       const bool compression_requested = request->response_compressed().value();
@@ -192,7 +192,7 @@ class TestServiceImpl : public TestService::Service {
 
   Status StreamingOutputCall(
       ServerContext* context, const StreamingOutputCallRequest* request,
-      ServerWriter<StreamingOutputCallResponse>* writer) {
+      ServerWriter<StreamingOutputCallResponse>* writer) override {
     StreamingOutputCallResponse response;
     bool write_success = true;
     for (int i = 0; write_success && i < request->response_parameters_size();
@@ -233,7 +233,7 @@ class TestServiceImpl : public TestService::Service {
 
   Status StreamingInputCall(ServerContext* context,
                             ServerReader<StreamingInputCallRequest>* reader,
-                            StreamingInputCallResponse* response) {
+                            StreamingInputCallResponse* response) override {
     StreamingInputCallRequest request;
     int aggregated_payload_size = 0;
     while (reader->Read(&request)) {
@@ -253,7 +253,7 @@ class TestServiceImpl : public TestService::Service {
   Status FullDuplexCall(
       ServerContext* context,
       ServerReaderWriter<StreamingOutputCallResponse,
-                         StreamingOutputCallRequest>* stream) {
+                         StreamingOutputCallRequest>* stream) override {
     MaybeEchoMetadata(context);
     StreamingOutputCallRequest request;
     StreamingOutputCallResponse response;
@@ -289,7 +289,7 @@ class TestServiceImpl : public TestService::Service {
   Status HalfDuplexCall(
       ServerContext* /*context*/,
       ServerReaderWriter<StreamingOutputCallResponse,
-                         StreamingOutputCallRequest>* stream) {
+                         StreamingOutputCallRequest>* stream) override {
     std::vector<StreamingOutputCallRequest> requests;
     StreamingOutputCallRequest request;
     while (stream->Read(&request)) {
diff --git a/test/cpp/interop/reconnect_interop_server.cc b/test/cpp/interop/reconnect_interop_server.cc
index 1e99d7cd9ab..d6b446d7947 100644
--- a/test/cpp/interop/reconnect_interop_server.cc
+++ b/test/cpp/interop/reconnect_interop_server.cc
@@ -69,7 +69,7 @@ class ReconnectServiceImpl : public ReconnectService::Service {
     reconnect_server_init(&tcp_server_);
   }
 
-  ~ReconnectServiceImpl() {
+  ~ReconnectServiceImpl() override {
     if (server_started_) {
       reconnect_server_destroy(&tcp_server_);
     }
@@ -78,7 +78,7 @@ class ReconnectServiceImpl : public ReconnectService::Service {
   void Poll(int seconds) { reconnect_server_poll(&tcp_server_, seconds); }
 
   Status Start(ServerContext* /*context*/, const ReconnectParams* request,
-               Empty* /*response*/) {
+               Empty* /*response*/) override {
     bool start_server = true;
     std::unique_lock<std::mutex> lock(mu_);
     while (serving_ && !shutdown_) {
@@ -106,7 +106,7 @@ class ReconnectServiceImpl : public ReconnectService::Service {
   }
 
   Status Stop(ServerContext* /*context*/, const Empty* /*request*/,
-              ReconnectInfo* response) {
+              ReconnectInfo* response) override {
     // extract timestamps and set response
     Verify(response);
     reconnect_server_clear_timestamps(&tcp_server_);
diff --git a/test/cpp/interop/xds_interop_client.cc b/test/cpp/interop/xds_interop_client.cc
index db36ff76344..92d3ac9da5a 100644
--- a/test/cpp/interop/xds_interop_client.cc
+++ b/test/cpp/interop/xds_interop_client.cc
@@ -271,7 +271,7 @@ class LoadBalancerStatsServiceImpl : public LoadBalancerStatsService::Service {
  public:
   Status GetClientStats(ServerContext* context,
                         const LoadBalancerStatsRequest* request,
-                        LoadBalancerStatsResponse* response) {
+                        LoadBalancerStatsResponse* response) override {
     int start_id;
     int end_id;
     XdsStatsWatcher* watcher;
diff --git a/test/cpp/interop/xds_interop_server.cc b/test/cpp/interop/xds_interop_server.cc
index 11a551e3cae..8e6f9bb5e3f 100644
--- a/test/cpp/interop/xds_interop_server.cc
+++ b/test/cpp/interop/xds_interop_server.cc
@@ -56,7 +56,7 @@ class TestServiceImpl : public TestService::Service {
   TestServiceImpl(const std::string& i) : hostname_(i) {}
 
   Status UnaryCall(ServerContext* context, const SimpleRequest* request,
-                   SimpleResponse* response) {
+                   SimpleResponse* response) override {
     response->set_server_id(FLAGS_server_id);
     response->set_hostname(hostname_);
     context->AddInitialMetadata("hostname", hostname_);
@@ -64,7 +64,7 @@ class TestServiceImpl : public TestService::Service {
   }
 
   Status EmptyCall(ServerContext* context, const Empty* request,
-                   Empty* response) {
+                   Empty* response) override {
     context->AddInitialMetadata("hostname", hostname_);
     return Status::OK;
   }
diff --git a/test/cpp/microbenchmarks/bm_call_create.cc b/test/cpp/microbenchmarks/bm_call_create.cc
index 0fd8e1bf1a3..4b114167c43 100644
--- a/test/cpp/microbenchmarks/bm_call_create.cc
+++ b/test/cpp/microbenchmarks/bm_call_create.cc
@@ -703,7 +703,7 @@ class IsolatedCallFixture : public TrackCounters {
     cq_ = grpc_completion_queue_create_for_next(nullptr);
   }
 
-  void Finish(benchmark::State& state) {
+  void Finish(benchmark::State& state) override {
     grpc_completion_queue_destroy(cq_);
     grpc_channel_destroy(channel_);
     TrackCounters::Finish(state);
diff --git a/test/cpp/microbenchmarks/bm_fullstack_trickle.cc b/test/cpp/microbenchmarks/bm_fullstack_trickle.cc
index a27b77f4a1e..b16e177506a 100644
--- a/test/cpp/microbenchmarks/bm_fullstack_trickle.cc
+++ b/test/cpp/microbenchmarks/bm_fullstack_trickle.cc
@@ -104,13 +104,13 @@ class TrickledCHTTP2 : public EndpointPairFixture {
     }
   }
 
-  virtual ~TrickledCHTTP2() {
+  ~TrickledCHTTP2() override {
     if (stats_ != nullptr) {
       grpc_passthru_endpoint_stats_destroy(stats_);
     }
   }
 
-  void AddToLabel(std::ostream& out, benchmark::State& state) {
+  void AddToLabel(std::ostream& out, benchmark::State& state) override {
     out << " writes/iter:"
         << ((double)stats_->num_writes / (double)state.iterations())
         << " cli_transport_stalls/iter:"
diff --git a/test/cpp/microbenchmarks/fullstack_fixtures.h b/test/cpp/microbenchmarks/fullstack_fixtures.h
index 73b4e41900e..9ba190b691f 100644
--- a/test/cpp/microbenchmarks/fullstack_fixtures.h
+++ b/test/cpp/microbenchmarks/fullstack_fixtures.h
@@ -84,7 +84,7 @@ class FullstackFixture : public BaseFixture {
     }
   }
 
-  virtual ~FullstackFixture() {
+  ~FullstackFixture() override {
     server_->Shutdown();
     cq_->Shutdown();
     void* tag;
@@ -93,7 +93,7 @@ class FullstackFixture : public BaseFixture {
     }
   }
 
-  void AddToLabel(std::ostream& out, benchmark::State& state) {
+  void AddToLabel(std::ostream& out, benchmark::State& state) override {
     BaseFixture::AddToLabel(out, state);
     out << " polls/iter:"
         << static_cast<double>(grpc_get_cq_poll_num(this->cq()->cq())) /
@@ -115,7 +115,7 @@ class TCP : public FullstackFixture {
                             FixtureConfiguration())
       : FullstackFixture(service, fixture_configuration, MakeAddress(&port_)) {}
 
-  ~TCP() { grpc_recycle_unused_port(port_); }
+  ~TCP() override { grpc_recycle_unused_port(port_); }
 
  private:
   int port_;
@@ -134,7 +134,7 @@ class UDS : public FullstackFixture {
                             FixtureConfiguration())
       : FullstackFixture(service, fixture_configuration, MakeAddress(&port_)) {}
 
-  ~UDS() { grpc_recycle_unused_port(port_); }
+  ~UDS() override { grpc_recycle_unused_port(port_); }
 
  private:
   int port_;
@@ -154,7 +154,7 @@ class InProcess : public FullstackFixture {
             const FixtureConfiguration& fixture_configuration =
                 FixtureConfiguration())
       : FullstackFixture(service, fixture_configuration, "") {}
-  ~InProcess() {}
+  ~InProcess() override {}
 };
 
 class EndpointPairFixture : public BaseFixture {
@@ -209,7 +209,7 @@ class EndpointPairFixture : public BaseFixture {
     }
   }
 
-  virtual ~EndpointPairFixture() {
+  ~EndpointPairFixture() override {
     server_->Shutdown();
     cq_->Shutdown();
     void* tag;
@@ -218,7 +218,7 @@ class EndpointPairFixture : public BaseFixture {
     }
   }
 
-  void AddToLabel(std::ostream& out, benchmark::State& state) {
+  void AddToLabel(std::ostream& out, benchmark::State& state) override {
     BaseFixture::AddToLabel(out, state);
     out << " polls/iter:"
         << static_cast<double>(grpc_get_cq_poll_num(this->cq()->cq())) /
@@ -261,13 +261,13 @@ class InProcessCHTTP2WithExplicitStats : public EndpointPairFixture {
                             fixture_configuration),
         stats_(stats) {}
 
-  virtual ~InProcessCHTTP2WithExplicitStats() {
+  ~InProcessCHTTP2WithExplicitStats() override {
     if (stats_ != nullptr) {
       grpc_passthru_endpoint_stats_destroy(stats_);
     }
   }
 
-  void AddToLabel(std::ostream& out, benchmark::State& state) {
+  void AddToLabel(std::ostream& out, benchmark::State& state) override {
     EndpointPairFixture::AddToLabel(out, state);
     out << " writes/iter:"
         << static_cast<double>(gpr_atm_no_barrier_load(&stats_->num_writes)) /
diff --git a/test/cpp/performance/writes_per_rpc_test.cc b/test/cpp/performance/writes_per_rpc_test.cc
index e262078e149..d3273ee7949 100644
--- a/test/cpp/performance/writes_per_rpc_test.cc
+++ b/test/cpp/performance/writes_per_rpc_test.cc
@@ -129,7 +129,7 @@ class InProcessCHTTP2 : public EndpointPairFixture {
   InProcessCHTTP2(Service* service, grpc_passthru_endpoint_stats* stats)
       : EndpointPairFixture(service, MakeEndpoints(stats)), stats_(stats) {}
 
-  virtual ~InProcessCHTTP2() {
+  ~InProcessCHTTP2() override {
     if (stats_ != nullptr) {
       grpc_passthru_endpoint_stats_destroy(stats_);
     }
diff --git a/test/cpp/qps/client.h b/test/cpp/qps/client.h
index 64f49827383..78e6c89fa17 100644
--- a/test/cpp/qps/client.h
+++ b/test/cpp/qps/client.h
@@ -441,7 +441,7 @@ class ClientImpl : public Client {
     ClientRequestCreator<RequestType> create_req(&request_,
                                                  config.payload_config());
   }
-  virtual ~ClientImpl() {}
+  ~ClientImpl() override {}
   const RequestType* request() { return &request_; }
 
   void WaitForChannelsToConnect() {
diff --git a/test/cpp/qps/client_async.cc b/test/cpp/qps/client_async.cc
index c3d9ae6de95..5c7c8a316b8 100644
--- a/test/cpp/qps/client_async.cc
+++ b/test/cpp/qps/client_async.cc
@@ -191,7 +191,7 @@ class AsyncClient : public ClientImpl<StubType, RequestType> {
       t = (t + 1) % cli_cqs_.size();
     }
   }
-  virtual ~AsyncClient() {
+  ~AsyncClient() override {
     for (auto cq = cli_cqs_.begin(); cq != cli_cqs_.end(); cq++) {
       void* got_tag;
       bool ok;
@@ -227,7 +227,7 @@ class AsyncClient : public ClientImpl<StubType, RequestType> {
     }
     return num_threads;
   }
-  void DestroyMultithreading() override final {
+  void DestroyMultithreading() final {
     for (auto ss = shutdown_state_.begin(); ss != shutdown_state_.end(); ++ss) {
       std::lock_guard<std::mutex> lock((*ss)->mutex);
       (*ss)->shutdown = true;
@@ -254,7 +254,7 @@ class AsyncClient : public ClientImpl<StubType, RequestType> {
     return ctx;
   }
 
-  void ThreadFunc(size_t thread_idx, Client::Thread* t) override final {
+  void ThreadFunc(size_t thread_idx, Client::Thread* t) final {
     void* got_tag;
     bool ok;
 
diff --git a/test/cpp/qps/client_callback.cc b/test/cpp/qps/client_callback.cc
index 047f2358c82..f8a26e49d4a 100644
--- a/test/cpp/qps/client_callback.cc
+++ b/test/cpp/qps/client_callback.cc
@@ -75,7 +75,7 @@ class CallbackClient
         config.client_channels() * config.outstanding_rpcs_per_channel();
   }
 
-  virtual ~CallbackClient() {}
+  ~CallbackClient() override {}
 
   /**
    * The main thread of the benchmark will be waiting on DestroyMultithreading.
@@ -151,7 +151,7 @@ class CallbackUnaryClient final : public CallbackClient {
     }
     StartThreads(num_threads_);
   }
-  ~CallbackUnaryClient() {}
+  ~CallbackUnaryClient() override {}
 
  protected:
   bool ThreadFuncImpl(Thread* t, size_t thread_idx) override {
@@ -223,7 +223,7 @@ class CallbackStreamingClient : public CallbackClient {
     }
     StartThreads(num_threads_);
   }
-  ~CallbackStreamingClient() {}
+  ~CallbackStreamingClient() override {}
 
   void AddHistogramEntry(double start, bool ok, Thread* thread_ptr) {
     // Update Histogram with data from the callback run
@@ -244,7 +244,7 @@ class CallbackStreamingPingPongClient : public CallbackStreamingClient {
  public:
   CallbackStreamingPingPongClient(const ClientConfig& config)
       : CallbackStreamingClient(config) {}
-  ~CallbackStreamingPingPongClient() {}
+  ~CallbackStreamingPingPongClient() override {}
 };
 
 class CallbackStreamingPingPongReactor final
@@ -346,7 +346,7 @@ class CallbackStreamingPingPongClientImpl final
       reactor_.emplace_back(
           new CallbackStreamingPingPongReactor(this, std::move(ctx_[i])));
   }
-  ~CallbackStreamingPingPongClientImpl() {}
+  ~CallbackStreamingPingPongClientImpl() override {}
 
   bool ThreadFuncImpl(Client::Thread* t, size_t thread_idx) override {
     for (size_t vector_idx = thread_idx; vector_idx < total_outstanding_rpcs_;
diff --git a/test/cpp/qps/client_sync.cc b/test/cpp/qps/client_sync.cc
index a0ec361c096..f042a035825 100644
--- a/test/cpp/qps/client_sync.cc
+++ b/test/cpp/qps/client_sync.cc
@@ -59,7 +59,7 @@ class SynchronousClient
     SetupLoadTest(config, num_threads_);
   }
 
-  virtual ~SynchronousClient() {}
+  ~SynchronousClient() override {}
 
   virtual bool InitThreadFuncImpl(size_t thread_idx) = 0;
   virtual bool ThreadFuncImpl(HistogramEntry* entry, size_t thread_idx) = 0;
@@ -115,7 +115,7 @@ class SynchronousUnaryClient final : public SynchronousClient {
       : SynchronousClient(config) {
     StartThreads(num_threads_);
   }
-  ~SynchronousUnaryClient() {}
+  ~SynchronousUnaryClient() override {}
 
   bool InitThreadFuncImpl(size_t /*thread_idx*/) override { return true; }
 
@@ -137,7 +137,7 @@ class SynchronousUnaryClient final : public SynchronousClient {
   }
 
  private:
-  void DestroyMultithreading() override final { EndThreads(); }
+  void DestroyMultithreading() final { EndThreads(); }
 };
 
 template <class StreamType>
@@ -153,7 +153,7 @@ class SynchronousStreamingClient : public SynchronousClient {
         messages_issued_(num_threads_) {
     StartThreads(num_threads_);
   }
-  virtual ~SynchronousStreamingClient() {
+  ~SynchronousStreamingClient() override {
     CleanupAllStreams([this](size_t thread_idx) {
       // Don't log any kind of error since we may have canceled this
       stream_[thread_idx]->Finish().IgnoreError();
@@ -208,7 +208,7 @@ class SynchronousStreamingClient : public SynchronousClient {
   }
 
  private:
-  void DestroyMultithreading() override final {
+  void DestroyMultithreading() final {
     CleanupAllStreams(
         [this](size_t thread_idx) { context_[thread_idx].TryCancel(); });
     EndThreads();
@@ -221,7 +221,7 @@ class SynchronousStreamingPingPongClient final
  public:
   SynchronousStreamingPingPongClient(const ClientConfig& config)
       : SynchronousStreamingClient(config) {}
-  ~SynchronousStreamingPingPongClient() {
+  ~SynchronousStreamingPingPongClient() override {
     CleanupAllStreams(
         [this](size_t thread_idx) { stream_[thread_idx]->WritesDone(); });
   }
@@ -278,7 +278,7 @@ class SynchronousStreamingFromClientClient final
  public:
   SynchronousStreamingFromClientClient(const ClientConfig& config)
       : SynchronousStreamingClient(config), last_issue_(num_threads_) {}
-  ~SynchronousStreamingFromClientClient() {
+  ~SynchronousStreamingFromClientClient() override {
     CleanupAllStreams(
         [this](size_t thread_idx) { stream_[thread_idx]->WritesDone(); });
   }
@@ -331,7 +331,7 @@ class SynchronousStreamingFromServerClient final
  public:
   SynchronousStreamingFromServerClient(const ClientConfig& config)
       : SynchronousStreamingClient(config), last_recv_(num_threads_) {}
-  ~SynchronousStreamingFromServerClient() {}
+  ~SynchronousStreamingFromServerClient() override {}
 
  private:
   std::vector<double> last_recv_;
@@ -377,7 +377,7 @@ class SynchronousStreamingBothWaysClient final
  public:
   SynchronousStreamingBothWaysClient(const ClientConfig& config)
       : SynchronousStreamingClient(config) {}
-  ~SynchronousStreamingBothWaysClient() {
+  ~SynchronousStreamingBothWaysClient() override {
     CleanupAllStreams(
         [this](size_t thread_idx) { stream_[thread_idx]->WritesDone(); });
   }
diff --git a/test/cpp/qps/server_async.cc b/test/cpp/qps/server_async.cc
index 51d410b1cbf..049fced1b29 100644
--- a/test/cpp/qps/server_async.cc
+++ b/test/cpp/qps/server_async.cc
@@ -162,7 +162,7 @@ class AsyncQpsServerTest final : public grpc::testing::Server {
       threads_.emplace_back(&AsyncQpsServerTest::ThreadFunc, this, i);
     }
   }
-  ~AsyncQpsServerTest() {
+  ~AsyncQpsServerTest() override {
     for (auto ss = shutdown_state_.begin(); ss != shutdown_state_.end(); ++ss) {
       std::lock_guard<std::mutex> lock((*ss)->mutex);
       (*ss)->shutdown = true;
diff --git a/test/cpp/util/channelz_sampler_test.cc b/test/cpp/util/channelz_sampler_test.cc
index 5a2751b58bc..efd01e78d40 100644
--- a/test/cpp/util/channelz_sampler_test.cc
+++ b/test/cpp/util/channelz_sampler_test.cc
@@ -66,7 +66,7 @@ std::string output_json("output.json");
 class EchoServerImpl final : public grpc::testing::TestService::Service {
   Status EmptyCall(::grpc::ServerContext* context,
                    const grpc::testing::Empty* request,
-                   grpc::testing::Empty* response) {
+                   grpc::testing::Empty* response) override {
     return Status::OK;
   }
 };
diff --git a/test/cpp/util/proto_reflection_descriptor_database.h b/test/cpp/util/proto_reflection_descriptor_database.h
index a1ceeadb3bd..c6dc62f571a 100644
--- a/test/cpp/util/proto_reflection_descriptor_database.h
+++ b/test/cpp/util/proto_reflection_descriptor_database.h
@@ -40,7 +40,7 @@ class ProtoReflectionDescriptorDatabase : public protobuf::DescriptorDatabase {
   explicit ProtoReflectionDescriptorDatabase(
       const std::shared_ptr<grpc::Channel>& channel);
 
-  virtual ~ProtoReflectionDescriptorDatabase();
+  ~ProtoReflectionDescriptorDatabase() override;
 
   // The following four methods implement DescriptorDatabase interfaces.
   //