diff --git a/modules/core/include/opencv2/core.hpp b/modules/core/include/opencv2/core.hpp
index b5beb7d2ea..216a8bcc92 100644
--- a/modules/core/include/opencv2/core.hpp
+++ b/modules/core/include/opencv2/core.hpp
@@ -124,7 +124,7 @@ public:
     /*!
      \return the error description and the context as a text string.
     */
-    virtual const char *what() const throw();
+    virtual const char *what() const throw() CV_OVERRIDE;
     void formatMessage();
 
     String msg; ///< the formatted error message
diff --git a/modules/core/include/opencv2/core/private.hpp b/modules/core/include/opencv2/core/private.hpp
index 5f4ffceeef..77eb4f9acb 100644
--- a/modules/core/include/opencv2/core/private.hpp
+++ b/modules/core/include/opencv2/core/private.hpp
@@ -165,6 +165,8 @@ template <typename T>
 T* allocSingleton(size_t count) { return static_cast<T*>(fastMalloc(sizeof(T) * count)); }
 }
 
+#if 1 // TODO: Remove in OpenCV 4.x
+
 // property implementation macros
 
 #define CV_IMPL_PROPERTY_RO(type, name, member) \
@@ -187,6 +189,8 @@ T* allocSingleton(size_t count) { return static_cast<T*>(fastMalloc(sizeof(T) *
 #define CV_WRAP_SAME_PROPERTY(type, name, internal_obj) CV_WRAP_PROPERTY(type, name, name, internal_obj)
 #define CV_WRAP_SAME_PROPERTY_S(type, name, internal_obj) CV_WRAP_PROPERTY_S(type, name, name, internal_obj)
 
+#endif
+
 /****************************************************************************************\
 *                     Structures and macros for integration with IPP                     *
 \****************************************************************************************/
diff --git a/modules/core/include/opencv2/core/ptr.inl.hpp b/modules/core/include/opencv2/core/ptr.inl.hpp
index 3c095a1f58..466f6342ec 100644
--- a/modules/core/include/opencv2/core/ptr.inl.hpp
+++ b/modules/core/include/opencv2/core/ptr.inl.hpp
@@ -89,12 +89,12 @@ private:
 };
 
 template<typename Y, typename D>
-struct PtrOwnerImpl : PtrOwner
+struct PtrOwnerImpl CV_FINAL : PtrOwner
 {
     PtrOwnerImpl(Y* p, D d) : owned(p), deleter(d)
     {}
 
-    void deleteSelf()
+    void deleteSelf() CV_OVERRIDE
     {
         deleter(owned);
         delete this;
diff --git a/modules/core/include/opencv2/core/utility.hpp b/modules/core/include/opencv2/core/utility.hpp
index 00bb68cce3..d7211d05bf 100644
--- a/modules/core/include/opencv2/core/utility.hpp
+++ b/modules/core/include/opencv2/core/utility.hpp
@@ -524,7 +524,7 @@ public:
         m_functor(functor)
     { }
 
-    virtual void operator() (const cv::Range& range) const
+    virtual void operator() (const cv::Range& range) const CV_OVERRIDE
     {
         m_functor(range);
     }
@@ -558,7 +558,8 @@ void Mat::forEach_impl(const Functor& operation) {
         virtual ~PixelOperationWrapper(){}
         // ! Overloaded virtual operator
         // convert range call to row call.
-        virtual void operator()(const Range &range) const {
+        virtual void operator()(const Range &range) const CV_OVERRIDE
+        {
             const int DIMS = mat->dims;
             const int COLS = mat->size[DIMS - 1];
             if (DIMS <= 2) {
@@ -711,8 +712,8 @@ public:
     inline void cleanup() { TLSDataContainer::cleanup(); }
 
 private:
-    virtual void* createDataInstance() const {return new T;}                // Wrapper to allocate data by template
-    virtual void  deleteDataInstance(void* pData) const {delete (T*)pData;} // Wrapper to release data by template
+    virtual void* createDataInstance() const CV_OVERRIDE {return new T;}                // Wrapper to allocate data by template
+    virtual void  deleteDataInstance(void* pData) const CV_OVERRIDE {delete (T*)pData;} // Wrapper to release data by template
 
     // Disable TLS copy operations
     TLSData(TLSData &) {}
diff --git a/modules/core/src/batch_distance.cpp b/modules/core/src/batch_distance.cpp
index c59ff78a07..807b7f0285 100644
--- a/modules/core/src/batch_distance.cpp
+++ b/modules/core/src/batch_distance.cpp
@@ -176,7 +176,7 @@ struct BatchDistInvoker : public ParallelLoopBody
         func = _func;
     }
 
-    void operator()(const Range& range) const
+    void operator()(const Range& range) const CV_OVERRIDE
     {
         AutoBuffer<int> buf(src2->rows);
         int* bufptr = buf;
diff --git a/modules/core/src/bufferpool.impl.hpp b/modules/core/src/bufferpool.impl.hpp
index 18a90e0691..0dcb31ac74 100644
--- a/modules/core/src/bufferpool.impl.hpp
+++ b/modules/core/src/bufferpool.impl.hpp
@@ -17,10 +17,10 @@ public:
     DummyBufferPoolController() { }
     virtual ~DummyBufferPoolController() { }
 
-    virtual size_t getReservedSize() const { return (size_t)-1; }
-    virtual size_t getMaxReservedSize() const { return (size_t)-1; }
-    virtual void setMaxReservedSize(size_t size) { (void)size; }
-    virtual void freeAllReservedBuffers() { }
+    virtual size_t getReservedSize() const CV_OVERRIDE { return (size_t)-1; }
+    virtual size_t getMaxReservedSize() const CV_OVERRIDE { return (size_t)-1; }
+    virtual void setMaxReservedSize(size_t size) CV_OVERRIDE { (void)size; }
+    virtual void freeAllReservedBuffers() CV_OVERRIDE { }
 };
 
 } // namespace
diff --git a/modules/core/src/conjugate_gradient.cpp b/modules/core/src/conjugate_gradient.cpp
index 3e6cffbbb2..400a5ab3a8 100644
--- a/modules/core/src/conjugate_gradient.cpp
+++ b/modules/core/src/conjugate_gradient.cpp
@@ -68,15 +68,15 @@ namespace cv
 
 #define SEC_METHOD_ITERATIONS 4
 #define INITIAL_SEC_METHOD_SIGMA 0.1
-    class ConjGradSolverImpl : public ConjGradSolver
+    class ConjGradSolverImpl CV_FINAL : public ConjGradSolver
     {
     public:
-        Ptr<Function> getFunction() const;
-        void setFunction(const Ptr<Function>& f);
-        TermCriteria getTermCriteria() const;
+        Ptr<Function> getFunction() const CV_OVERRIDE;
+        void setFunction(const Ptr<Function>& f) CV_OVERRIDE;
+        TermCriteria getTermCriteria() const CV_OVERRIDE;
         ConjGradSolverImpl();
-        void setTermCriteria(const TermCriteria& termcrit);
-        double minimize(InputOutputArray x);
+        void setTermCriteria(const TermCriteria& termcrit) CV_OVERRIDE;
+        double minimize(InputOutputArray x) CV_OVERRIDE;
     protected:
         Ptr<MinProblemSolver::Function> _Function;
         TermCriteria _termcrit;
diff --git a/modules/core/src/downhill_simplex.cpp b/modules/core/src/downhill_simplex.cpp
index a830d02812..15d6469465 100644
--- a/modules/core/src/downhill_simplex.cpp
+++ b/modules/core/src/downhill_simplex.cpp
@@ -140,7 +140,7 @@ multiple lines in three dimensions as not all lines intersect in three dimension
 namespace cv
 {
 
-class DownhillSolverImpl : public DownhillSolver
+class DownhillSolverImpl CV_FINAL : public DownhillSolver
 {
 public:
     DownhillSolverImpl()
@@ -149,8 +149,8 @@ public:
         _step=Mat_<double>();
     }
 
-    void getInitStep(OutputArray step) const { _step.copyTo(step); }
-    void setInitStep(InputArray step)
+    void getInitStep(OutputArray step) const CV_OVERRIDE { _step.copyTo(step); }
+    void setInitStep(InputArray step) CV_OVERRIDE
     {
         // set dimensionality and make a deep copy of step
         Mat m = step.getMat();
@@ -161,13 +161,13 @@ public:
             transpose(m, _step);
     }
 
-    Ptr<MinProblemSolver::Function> getFunction() const { return _Function; }
+    Ptr<MinProblemSolver::Function> getFunction() const CV_OVERRIDE { return _Function; }
 
-    void setFunction(const Ptr<Function>& f) { _Function=f; }
+    void setFunction(const Ptr<Function>& f) CV_OVERRIDE { _Function=f; }
 
-    TermCriteria getTermCriteria() const { return _termcrit; }
+    TermCriteria getTermCriteria() const CV_OVERRIDE { return _termcrit; }
 
-    void setTermCriteria( const TermCriteria& termcrit )
+    void setTermCriteria( const TermCriteria& termcrit ) CV_OVERRIDE
     {
         CV_Assert( termcrit.type == (TermCriteria::MAX_ITER + TermCriteria::EPS) &&
                    termcrit.epsilon > 0 &&
@@ -175,7 +175,7 @@ public:
         _termcrit=termcrit;
     }
 
-    double minimize( InputOutputArray x_ )
+    double minimize( InputOutputArray x_ ) CV_OVERRIDE
     {
         dprintf(("hi from minimize\n"));
         CV_Assert( !_Function.empty() );
diff --git a/modules/core/src/dxt.cpp b/modules/core/src/dxt.cpp
index d7374e2388..a161f86885 100644
--- a/modules/core/src/dxt.cpp
+++ b/modules/core/src/dxt.cpp
@@ -1562,7 +1562,7 @@ public:
         *ok = true;
     }
 
-    virtual void operator()(const Range& range) const
+    virtual void operator()(const Range& range) const CV_OVERRIDE
     {
         IppStatus status;
         Ipp8u* pBuffer = 0;
@@ -1643,7 +1643,7 @@ public:
         *ok = true;
     }
 
-    virtual void operator()(const Range& range) const
+    virtual void operator()(const Range& range) const CV_OVERRIDE
     {
         IppStatus status;
         Ipp8u* pBuffer = 0;
@@ -2607,7 +2607,7 @@ inline DftDims determineDims(int rows, int cols, bool isRowWise, bool isContinuo
     return InvalidDim;
 }
 
-class OcvDftImpl : public hal::DFT2D
+class OcvDftImpl CV_FINAL : public hal::DFT2D
 {
 protected:
     Ptr<hal::DFT1D> contextA;
@@ -2779,7 +2779,7 @@ public:
         }
     }
 
-    void apply(const uchar * src, size_t src_step, uchar * dst, size_t dst_step)
+    void apply(const uchar * src, size_t src_step, uchar * dst, size_t dst_step) CV_OVERRIDE
     {
 #if defined USE_IPP_DFT
         if (useIpp)
@@ -3039,7 +3039,7 @@ protected:
     }
 };
 
-class OcvDftBasicImpl : public hal::DFT1D
+class OcvDftBasicImpl CV_FINAL : public hal::DFT1D
 {
 public:
     OcvDftOptions opt;
@@ -3194,7 +3194,7 @@ public:
         }
     }
 
-    void apply(const uchar *src, uchar *dst)
+    void apply(const uchar *src, uchar *dst) CV_OVERRIDE
     {
         opt.dft_func(opt, src, dst);
     }
@@ -3214,7 +3214,7 @@ struct ReplacementDFT1D : public hal::DFT1D
         isInitialized = (res == CV_HAL_ERROR_OK);
         return isInitialized;
     }
-    void apply(const uchar *src, uchar *dst)
+    void apply(const uchar *src, uchar *dst) CV_OVERRIDE
     {
         if (isInitialized)
         {
@@ -3244,7 +3244,7 @@ struct ReplacementDFT2D : public hal::DFT2D
         isInitialized = (res == CV_HAL_ERROR_OK);
         return isInitialized;
     }
-    void apply(const uchar *src, size_t src_step, uchar *dst, size_t dst_step)
+    void apply(const uchar *src, size_t src_step, uchar *dst, size_t dst_step) CV_OVERRIDE
     {
         if (isInitialized)
         {
@@ -3809,7 +3809,7 @@ public:
         *ok = true;
     }
 
-    virtual void operator()(const Range& range) const
+    virtual void operator()(const Range& range) const CV_OVERRIDE
     {
         if(*ok == false)
             return;
@@ -4048,7 +4048,7 @@ static bool ippi_DCT_32f(const uchar * src, size_t src_step, uchar * dst, size_t
 
 namespace cv {
 
-class OcvDctImpl : public hal::DCT2D
+class OcvDctImpl CV_FINAL : public hal::DCT2D
 {
 public:
     OcvDftOptions opt;
@@ -4100,7 +4100,7 @@ public:
             end_stage = 1;
         }
     }
-    void apply(const uchar *src, size_t src_step, uchar *dst, size_t dst_step)
+    void apply(const uchar *src, size_t src_step, uchar *dst, size_t dst_step) CV_OVERRIDE
     {
         CV_IPP_RUN(IPP_VERSION_X100 >= 700 && depth == CV_32F, ippi_DCT_32f(src, src_step, dst, dst_step, width, height, isInverse, isRowTransform))
 
@@ -4196,7 +4196,7 @@ struct ReplacementDCT2D : public hal::DCT2D
         isInitialized = (res == CV_HAL_ERROR_OK);
         return isInitialized;
     }
-    void apply(const uchar *src_data, size_t src_step, uchar *dst_data, size_t dst_step)
+    void apply(const uchar *src_data, size_t src_step, uchar *dst_data, size_t dst_step) CV_OVERRIDE
     {
         if (isInitialized)
         {
diff --git a/modules/core/src/kmeans.cpp b/modules/core/src/kmeans.cpp
index 9613971d6b..6b1a110c1f 100644
--- a/modules/core/src/kmeans.cpp
+++ b/modules/core/src/kmeans.cpp
@@ -65,7 +65,7 @@ public:
         tdist2(tdist2_), data(data_), dist(dist_), ci(ci_)
     { }
 
-    void operator()( const cv::Range& range ) const
+    void operator()( const cv::Range& range ) const CV_OVERRIDE
     {
         CV_TRACE_FUNCTION();
         const int begin = range.start;
@@ -171,7 +171,7 @@ public:
     {
     }
 
-    void operator()( const Range& range ) const
+    void operator()(const Range& range) const CV_OVERRIDE
     {
         CV_TRACE_FUNCTION();
         const int begin = range.start;
diff --git a/modules/core/src/lut.cpp b/modules/core/src/lut.cpp
index fb6386524a..71f06ea5b2 100644
--- a/modules/core/src/lut.cpp
+++ b/modules/core/src/lut.cpp
@@ -328,7 +328,7 @@ public:
         *ok = (func != NULL);
     }
 
-    void operator()( const cv::Range& range ) const
+    void operator()( const cv::Range& range ) const CV_OVERRIDE
     {
         CV_DbgAssert(*ok);
 
diff --git a/modules/core/src/matrix.cpp b/modules/core/src/matrix.cpp
index 8984dc99ec..f9c4044614 100644
--- a/modules/core/src/matrix.cpp
+++ b/modules/core/src/matrix.cpp
@@ -123,11 +123,11 @@ BufferPoolController* MatAllocator::getBufferPoolController(const char* id) cons
     return &dummy;
 }
 
-class StdMatAllocator : public MatAllocator
+class StdMatAllocator CV_FINAL : public MatAllocator
 {
 public:
     UMatData* allocate(int dims, const int* sizes, int type,
-                       void* data0, size_t* step, int /*flags*/, UMatUsageFlags /*usageFlags*/) const
+                       void* data0, size_t* step, int /*flags*/, UMatUsageFlags /*usageFlags*/) const CV_OVERRIDE
     {
         size_t total = CV_ELEM_SIZE(type);
         for( int i = dims-1; i >= 0; i-- )
@@ -154,13 +154,13 @@ public:
         return u;
     }
 
-    bool allocate(UMatData* u, int /*accessFlags*/, UMatUsageFlags /*usageFlags*/) const
+    bool allocate(UMatData* u, int /*accessFlags*/, UMatUsageFlags /*usageFlags*/) const CV_OVERRIDE
     {
         if(!u) return false;
         return true;
     }
 
-    void deallocate(UMatData* u) const
+    void deallocate(UMatData* u) const CV_OVERRIDE
     {
         if(!u)
             return;
diff --git a/modules/core/src/matrix_expressions.cpp b/modules/core/src/matrix_expressions.cpp
index 5287bf585e..88d471f383 100644
--- a/modules/core/src/matrix_expressions.cpp
+++ b/modules/core/src/matrix_expressions.cpp
@@ -14,53 +14,53 @@
 namespace cv
 {
 
-class MatOp_Identity : public MatOp
+class MatOp_Identity CV_FINAL : public MatOp
 {
 public:
     MatOp_Identity() {}
     virtual ~MatOp_Identity() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return true; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return true; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, const Mat& m);
 };
 
 static MatOp_Identity g_MatOp_Identity;
 
-class MatOp_AddEx : public MatOp
+class MatOp_AddEx CV_FINAL : public MatOp
 {
 public:
     MatOp_AddEx() {}
     virtual ~MatOp_AddEx() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return true; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return true; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
-    void add(const MatExpr& e1, const Scalar& s, MatExpr& res) const;
-    void subtract(const Scalar& s, const MatExpr& expr, MatExpr& res) const;
-    void multiply(const MatExpr& e1, double s, MatExpr& res) const;
-    void divide(double s, const MatExpr& e, MatExpr& res) const;
+    void add(const MatExpr& e1, const Scalar& s, MatExpr& res) const CV_OVERRIDE;
+    void subtract(const Scalar& s, const MatExpr& expr, MatExpr& res) const CV_OVERRIDE;
+    void multiply(const MatExpr& e1, double s, MatExpr& res) const CV_OVERRIDE;
+    void divide(double s, const MatExpr& e, MatExpr& res) const CV_OVERRIDE;
 
-    void transpose(const MatExpr& e1, MatExpr& res) const;
-    void abs(const MatExpr& expr, MatExpr& res) const;
+    void transpose(const MatExpr& e1, MatExpr& res) const CV_OVERRIDE;
+    void abs(const MatExpr& expr, MatExpr& res) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, const Mat& a, const Mat& b, double alpha, double beta, const Scalar& s=Scalar());
 };
 
 static MatOp_AddEx g_MatOp_AddEx;
 
-class MatOp_Bin : public MatOp
+class MatOp_Bin CV_FINAL : public MatOp
 {
 public:
     MatOp_Bin() {}
     virtual ~MatOp_Bin() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return true; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return true; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
-    void multiply(const MatExpr& e1, double s, MatExpr& res) const;
-    void divide(double s, const MatExpr& e, MatExpr& res) const;
+    void multiply(const MatExpr& e1, double s, MatExpr& res) const CV_OVERRIDE;
+    void divide(double s, const MatExpr& e, MatExpr& res) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, char op, const Mat& a, const Mat& b, double scale=1);
     static void makeExpr(MatExpr& res, char op, const Mat& a, const Scalar& s);
@@ -68,14 +68,14 @@ public:
 
 static MatOp_Bin g_MatOp_Bin;
 
-class MatOp_Cmp : public MatOp
+class MatOp_Cmp CV_FINAL : public MatOp
 {
 public:
     MatOp_Cmp() {}
     virtual ~MatOp_Cmp() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return true; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return true; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, int cmpop, const Mat& a, const Mat& b);
     static void makeExpr(MatExpr& res, int cmpop, const Mat& a, double alpha);
@@ -83,20 +83,20 @@ public:
 
 static MatOp_Cmp g_MatOp_Cmp;
 
-class MatOp_GEMM : public MatOp
+class MatOp_GEMM CV_FINAL : public MatOp
 {
 public:
     MatOp_GEMM() {}
     virtual ~MatOp_GEMM() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return false; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return false; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
-    void add(const MatExpr& e1, const MatExpr& e2, MatExpr& res) const;
-    void subtract(const MatExpr& e1, const MatExpr& e2, MatExpr& res) const;
-    void multiply(const MatExpr& e, double s, MatExpr& res) const;
+    void add(const MatExpr& e1, const MatExpr& e2, MatExpr& res) const CV_OVERRIDE;
+    void subtract(const MatExpr& e1, const MatExpr& e2, MatExpr& res) const CV_OVERRIDE;
+    void multiply(const MatExpr& e, double s, MatExpr& res) const CV_OVERRIDE;
 
-    void transpose(const MatExpr& expr, MatExpr& res) const;
+    void transpose(const MatExpr& expr, MatExpr& res) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, int flags, const Mat& a, const Mat& b,
                          double alpha=1, const Mat& c=Mat(), double beta=1);
@@ -104,63 +104,63 @@ public:
 
 static MatOp_GEMM g_MatOp_GEMM;
 
-class MatOp_Invert : public MatOp
+class MatOp_Invert CV_FINAL : public MatOp
 {
 public:
     MatOp_Invert() {}
     virtual ~MatOp_Invert() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return false; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return false; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
-    void matmul(const MatExpr& expr1, const MatExpr& expr2, MatExpr& res) const;
+    void matmul(const MatExpr& expr1, const MatExpr& expr2, MatExpr& res) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, int method, const Mat& m);
 };
 
 static MatOp_Invert g_MatOp_Invert;
 
-class MatOp_T : public MatOp
+class MatOp_T CV_FINAL : public MatOp
 {
 public:
     MatOp_T() {}
     virtual ~MatOp_T() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return false; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return false; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
-    void multiply(const MatExpr& e1, double s, MatExpr& res) const;
-    void transpose(const MatExpr& expr, MatExpr& res) const;
+    void multiply(const MatExpr& e1, double s, MatExpr& res) const CV_OVERRIDE;
+    void transpose(const MatExpr& expr, MatExpr& res) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, const Mat& a, double alpha=1);
 };
 
 static MatOp_T g_MatOp_T;
 
-class MatOp_Solve : public MatOp
+class MatOp_Solve CV_FINAL : public MatOp
 {
 public:
     MatOp_Solve() {}
     virtual ~MatOp_Solve() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return false; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return false; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, int method, const Mat& a, const Mat& b);
 };
 
 static MatOp_Solve g_MatOp_Solve;
 
-class MatOp_Initializer : public MatOp
+class MatOp_Initializer CV_FINAL : public MatOp
 {
 public:
     MatOp_Initializer() {}
     virtual ~MatOp_Initializer() {}
 
-    bool elementWise(const MatExpr& /*expr*/) const { return false; }
-    void assign(const MatExpr& expr, Mat& m, int type=-1) const;
+    bool elementWise(const MatExpr& /*expr*/) const CV_OVERRIDE { return false; }
+    void assign(const MatExpr& expr, Mat& m, int type=-1) const CV_OVERRIDE;
 
-    void multiply(const MatExpr& e, double s, MatExpr& res) const;
+    void multiply(const MatExpr& e, double s, MatExpr& res) const CV_OVERRIDE;
 
     static void makeExpr(MatExpr& res, int method, Size sz, int type, double alpha=1);
     static void makeExpr(MatExpr& res, int method, int ndims, const int* sizes, int type, double alpha=1);
diff --git a/modules/core/src/ocl.cpp b/modules/core/src/ocl.cpp
index e17464e3cb..cc659302e7 100644
--- a/modules/core/src/ocl.cpp
+++ b/modules/core/src/ocl.cpp
@@ -4178,7 +4178,7 @@ public:
         CV_Assert(reservedEntries_.empty());
     }
 public:
-    virtual T allocate(size_t size)
+    virtual T allocate(size_t size) CV_OVERRIDE
     {
         AutoLock locker(mutex_);
         BufferEntry entry;
@@ -4193,7 +4193,7 @@ public:
         }
         return entry.clBuffer_;
     }
-    virtual void release(T buffer)
+    virtual void release(T buffer) CV_OVERRIDE
     {
         AutoLock locker(mutex_);
         BufferEntry entry;
@@ -4210,9 +4210,9 @@ public:
         }
     }
 
-    virtual size_t getReservedSize() const { return currentReservedSize; }
-    virtual size_t getMaxReservedSize() const { return maxReservedSize; }
-    virtual void setMaxReservedSize(size_t size)
+    virtual size_t getReservedSize() const CV_OVERRIDE { return currentReservedSize; }
+    virtual size_t getMaxReservedSize() const CV_OVERRIDE { return maxReservedSize; }
+    virtual void setMaxReservedSize(size_t size) CV_OVERRIDE
     {
         AutoLock locker(mutex_);
         size_t oldMaxReservedSize = maxReservedSize;
@@ -4236,7 +4236,7 @@ public:
             _checkSizeOfReservedEntries();
         }
     }
-    virtual void freeAllReservedBuffers()
+    virtual void freeAllReservedBuffers() CV_OVERRIDE
     {
         AutoLock locker(mutex_);
         typename std::list<BufferEntry>::const_iterator i = reservedEntries_.begin();
@@ -4257,7 +4257,7 @@ struct CLBufferEntry
     CLBufferEntry() : clBuffer_((cl_mem)NULL), capacity_(0) { }
 };
 
-class OpenCLBufferPoolImpl : public OpenCLBufferPoolBaseImpl<OpenCLBufferPoolImpl, CLBufferEntry, cl_mem>
+class OpenCLBufferPoolImpl CV_FINAL : public OpenCLBufferPoolBaseImpl<OpenCLBufferPoolImpl, CLBufferEntry, cl_mem>
 {
 public:
     typedef struct CLBufferEntry BufferEntry;
@@ -4303,7 +4303,7 @@ struct CLSVMBufferEntry
     size_t capacity_;
     CLSVMBufferEntry() : clBuffer_(NULL), capacity_(0) { }
 };
-class OpenCLSVMBufferPoolImpl : public OpenCLBufferPoolBaseImpl<OpenCLSVMBufferPoolImpl, CLSVMBufferEntry, void*>
+class OpenCLSVMBufferPoolImpl CV_FINAL : public OpenCLBufferPoolBaseImpl<OpenCLSVMBufferPoolImpl, CLSVMBufferEntry, void*>
 {
 public:
     typedef struct CLSVMBufferEntry BufferEntry;
@@ -4465,7 +4465,7 @@ private:
 #define CV_OPENCL_DATA_PTR_ALIGNMENT 16
 #endif
 
-class OpenCLAllocator : public MatAllocator
+class OpenCLAllocator CV_FINAL : public MatAllocator
 {
     mutable OpenCLBufferPoolImpl bufferPool;
     mutable OpenCLBufferPoolImpl bufferPoolHostPtr;
@@ -4525,7 +4525,7 @@ public:
     }
 
     UMatData* allocate(int dims, const int* sizes, int type,
-                       void* data, size_t* step, int flags, UMatUsageFlags usageFlags) const
+                       void* data, size_t* step, int flags, UMatUsageFlags usageFlags) const CV_OVERRIDE
     {
         if(!useOpenCL())
             return defaultAllocate(dims, sizes, type, data, step, flags, usageFlags);
@@ -4589,7 +4589,7 @@ public:
         return u;
     }
 
-    bool allocate(UMatData* u, int accessFlags, UMatUsageFlags usageFlags) const
+    bool allocate(UMatData* u, int accessFlags, UMatUsageFlags usageFlags) const CV_OVERRIDE
     {
         if(!u)
             return false;
@@ -4721,7 +4721,7 @@ public:
         }
     }*/
 
-    void deallocate(UMatData* u) const
+    void deallocate(UMatData* u) const CV_OVERRIDE
     {
         if(!u)
             return;
@@ -4905,7 +4905,7 @@ public:
     }
 
     // synchronized call (external UMatDataAutoLock, see UMat::getMat)
-    void map(UMatData* u, int accessFlags) const
+    void map(UMatData* u, int accessFlags) const CV_OVERRIDE
     {
         CV_Assert(u && u->handle);
 
@@ -4988,7 +4988,7 @@ public:
         }
     }
 
-    void unmap(UMatData* u) const
+    void unmap(UMatData* u) const CV_OVERRIDE
     {
         if(!u)
             return;
@@ -5133,7 +5133,7 @@ public:
 
     void download(UMatData* u, void* dstptr, int dims, const size_t sz[],
                   const size_t srcofs[], const size_t srcstep[],
-                  const size_t dststep[]) const
+                  const size_t dststep[]) const CV_OVERRIDE
     {
         if(!u)
             return;
@@ -5256,7 +5256,7 @@ public:
 
     void upload(UMatData* u, const void* srcptr, int dims, const size_t sz[],
                 const size_t dstofs[], const size_t dststep[],
-                const size_t srcstep[]) const
+                const size_t srcstep[]) const CV_OVERRIDE
     {
         if(!u)
             return;
@@ -5408,7 +5408,7 @@ public:
 
     void copy(UMatData* src, UMatData* dst, int dims, const size_t sz[],
               const size_t srcofs[], const size_t srcstep[],
-              const size_t dstofs[], const size_t dststep[], bool _sync) const
+              const size_t dstofs[], const size_t dststep[], bool _sync) const CV_OVERRIDE
     {
         if(!src || !dst)
             return;
@@ -5596,7 +5596,7 @@ public:
         }
     }
 
-    BufferPoolController* getBufferPoolController(const char* id) const {
+    BufferPoolController* getBufferPoolController(const char* id) const CV_OVERRIDE {
 #ifdef HAVE_OPENCL_SVM
         if ((svm::checkForceSVMUmatUsage() && (id == NULL || strcmp(id, "OCL") == 0)) || (id != NULL && strcmp(id, "SVM") == 0))
         {
diff --git a/modules/core/src/out.cpp b/modules/core/src/out.cpp
index 77c55aba82..9f28654358 100644
--- a/modules/core/src/out.cpp
+++ b/modules/core/src/out.cpp
@@ -45,7 +45,7 @@
 
 namespace cv
 {
-    class FormattedImpl : public Formatted
+    class FormattedImpl CV_FINAL : public Formatted
     {
         enum { STATE_PROLOGUE, STATE_EPILOGUE, STATE_INTERLUDE,
                STATE_ROW_OPEN, STATE_ROW_CLOSE, STATE_CN_OPEN, STATE_CN_CLOSE, STATE_VALUE, STATE_FINISHED,
@@ -119,12 +119,12 @@ namespace cv
             }
         }
 
-        void reset()
+        void reset() CV_OVERRIDE
         {
             state = STATE_PROLOGUE;
         }
 
-        const char* next()
+        const char* next() CV_OVERRIDE
         {
             switch(state)
             {
@@ -258,17 +258,17 @@ namespace cv
     public:
         FormatterBase() : prec32f(8), prec64f(16), multiline(true) {}
 
-        void set32fPrecision(int p)
+        void set32fPrecision(int p) CV_OVERRIDE
         {
             prec32f = p;
         }
 
-        void set64fPrecision(int p)
+        void set64fPrecision(int p) CV_OVERRIDE
         {
             prec64f = p;
         }
 
-        void setMultiline(bool ml)
+        void setMultiline(bool ml) CV_OVERRIDE
         {
             multiline = ml;
         }
@@ -279,11 +279,11 @@ namespace cv
         int multiline;
     };
 
-    class DefaultFormatter : public FormatterBase
+    class DefaultFormatter CV_FINAL : public FormatterBase
     {
     public:
 
-        Ptr<Formatted> format(const Mat& mtx) const
+        Ptr<Formatted> format(const Mat& mtx) const CV_OVERRIDE
         {
             char braces[5] = {'\0', '\0', ';', '\0', '\0'};
             return makePtr<FormattedImpl>("[", "]", mtx, &*braces,
@@ -291,11 +291,11 @@ namespace cv
         }
     };
 
-    class MatlabFormatter : public FormatterBase
+    class MatlabFormatter CV_FINAL : public FormatterBase
     {
     public:
 
-        Ptr<Formatted> format(const Mat& mtx) const
+        Ptr<Formatted> format(const Mat& mtx) const CV_OVERRIDE
         {
             char braces[5] = {'\0', '\0', ';', '\0', '\0'};
             return makePtr<FormattedImpl>("", "", mtx, &*braces,
@@ -303,11 +303,11 @@ namespace cv
         }
     };
 
-    class PythonFormatter : public FormatterBase
+    class PythonFormatter CV_FINAL : public FormatterBase
     {
     public:
 
-        Ptr<Formatted> format(const Mat& mtx) const
+        Ptr<Formatted> format(const Mat& mtx) const CV_OVERRIDE
         {
             char braces[5] = {'[', ']', ',', '[', ']'};
             if (mtx.cols == 1)
@@ -317,11 +317,11 @@ namespace cv
         }
     };
 
-    class NumpyFormatter : public FormatterBase
+    class NumpyFormatter CV_FINAL : public FormatterBase
     {
     public:
 
-        Ptr<Formatted> format(const Mat& mtx) const
+        Ptr<Formatted> format(const Mat& mtx) const CV_OVERRIDE
         {
             static const char* numpyTypes[] =
             {
@@ -336,11 +336,11 @@ namespace cv
         }
     };
 
-    class CSVFormatter : public FormatterBase
+    class CSVFormatter CV_FINAL : public FormatterBase
     {
     public:
 
-        Ptr<Formatted> format(const Mat& mtx) const
+        Ptr<Formatted> format(const Mat& mtx) const CV_OVERRIDE
         {
             char braces[5] = {'\0', '\0', '\0', '\0', '\0'};
             return makePtr<FormattedImpl>(String(),
@@ -349,11 +349,11 @@ namespace cv
         }
     };
 
-    class CFormatter : public FormatterBase
+    class CFormatter CV_FINAL : public FormatterBase
     {
     public:
 
-        Ptr<Formatted> format(const Mat& mtx) const
+        Ptr<Formatted> format(const Mat& mtx) const CV_OVERRIDE
         {
             char braces[5] = {'\0', '\0', ',', '\0', '\0'};
             return makePtr<FormattedImpl>("{", "}", mtx, &*braces,
diff --git a/modules/core/src/parallel.cpp b/modules/core/src/parallel.cpp
index 7ef2fdc5ed..5b5e859689 100644
--- a/modules/core/src/parallel.cpp
+++ b/modules/core/src/parallel.cpp
@@ -238,7 +238,7 @@ namespace
         ~ParallelLoopBodyWrapper()
         {
         }
-        void operator()(const cv::Range& sr) const
+        void operator()(const cv::Range& sr) const CV_OVERRIDE
         {
 #ifdef OPENCV_TRACE
             // TODO CV_TRACE_NS::details::setCurrentRegion(rootRegion);
diff --git a/modules/core/src/trace.cpp b/modules/core/src/trace.cpp
index a8fd26db05..dc15bd31d2 100644
--- a/modules/core/src/trace.cpp
+++ b/modules/core/src/trace.cpp
@@ -726,7 +726,7 @@ void TraceManagerThreadLocal::dumpStack(std::ostream& out, bool onlyFunctions) c
     out << ss.str();
 }
 
-class AsyncTraceStorage : public TraceStorage
+class AsyncTraceStorage CV_FINAL : public TraceStorage
 {
     mutable std::ofstream out;
 public:
@@ -744,7 +744,7 @@ public:
         out.close();
     }
 
-    bool put(const TraceMessage& msg) const
+    bool put(const TraceMessage& msg) const CV_OVERRIDE
     {
         if (msg.hasError)
             return false;
@@ -754,7 +754,7 @@ public:
     }
 };
 
-class SyncTraceStorage : public TraceStorage
+class SyncTraceStorage CV_FINAL : public TraceStorage
 {
     mutable std::ofstream out;
     mutable cv::Mutex mutex;
@@ -774,7 +774,7 @@ public:
         out.close();
     }
 
-    bool put(const TraceMessage& msg) const
+    bool put(const TraceMessage& msg) const CV_OVERRIDE
     {
         if (msg.hasError)
             return false;