diff --git a/Protobuf-C++.podspec b/Protobuf-C++.podspec
index c235e001a2..4a524e68d7 100644
--- a/Protobuf-C++.podspec
+++ b/Protobuf-C++.podspec
@@ -1,6 +1,6 @@
 Pod::Spec.new do |s|
   s.name     = 'Protobuf-C++'
-  s.version  = '3.18.0-rc2'
+  s.version  = '3.18.0'
   s.summary  = 'Protocol Buffers v3 runtime library for C++.'
   s.homepage = 'https://github.com/google/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/Protobuf.podspec b/Protobuf.podspec
index e1e6e6db3a..a3c4380884 100644
--- a/Protobuf.podspec
+++ b/Protobuf.podspec
@@ -5,7 +5,7 @@
 # dependent projects use the :git notation to refer to the library.
 Pod::Spec.new do |s|
   s.name     = 'Protobuf'
-  s.version  = '3.18.0-rc2'
+  s.version  = '3.18.0'
   s.summary  = 'Protocol Buffers v.3 runtime library for Objective-C.'
   s.homepage = 'https://github.com/protocolbuffers/protobuf'
   s.license  = '3-Clause BSD License'
diff --git a/configure.ac b/configure.ac
index 7bddc5036b..829568f76d 100644
--- a/configure.ac
+++ b/configure.ac
@@ -17,7 +17,7 @@ AC_PREREQ(2.59)
 # In the SVN trunk, the version should always be the next anticipated release
 # version with the "-pre" suffix.  (We used to use "-SNAPSHOT" but this pushed
 # the size of one file name in the dist tarfile over the 99-char limit.)
-AC_INIT([Protocol Buffers],[3.18.0-rc-2],[protobuf@googlegroups.com],[protobuf])
+AC_INIT([Protocol Buffers],[3.18.0],[protobuf@googlegroups.com],[protobuf])
 
 AM_MAINTAINER_MODE([enable])
 
diff --git a/csharp/Google.Protobuf.Tools.nuspec b/csharp/Google.Protobuf.Tools.nuspec
index 1494037ef2..11b6618abe 100644
--- a/csharp/Google.Protobuf.Tools.nuspec
+++ b/csharp/Google.Protobuf.Tools.nuspec
@@ -5,7 +5,7 @@
     <title>Google Protocol Buffers tools</title>
     <summary>Tools for Protocol Buffers - Google's data interchange format.</summary>
     <description>See project site for more info.</description>
-    <version>3.18.0-rc2</version>
+    <version>3.18.0</version>
     <authors>Google Inc.</authors>
     <owners>protobuf-packages</owners>
     <licenseUrl>https://github.com/protocolbuffers/protobuf/blob/master/LICENSE</licenseUrl>
diff --git a/csharp/src/Google.Protobuf/Google.Protobuf.csproj b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
index 9cb3088f55..c5996a5dfe 100644
--- a/csharp/src/Google.Protobuf/Google.Protobuf.csproj
+++ b/csharp/src/Google.Protobuf/Google.Protobuf.csproj
@@ -4,7 +4,7 @@
     <Description>C# runtime library for Protocol Buffers - Google's data interchange format.</Description>
     <Copyright>Copyright 2015, Google Inc.</Copyright>
     <AssemblyTitle>Google Protocol Buffers</AssemblyTitle>
-    <VersionPrefix>3.18.0-rc2</VersionPrefix>
+    <VersionPrefix>3.18.0</VersionPrefix>
     <!-- C# 7.2 is required for Span/BufferWriter/ReadOnlySequence -->
     <LangVersion>7.2</LangVersion>
     <Authors>Google Inc.</Authors>
diff --git a/java/bom/pom.xml b/java/bom/pom.xml
index 7708469d68..6b624ec993 100644
--- a/java/bom/pom.xml
+++ b/java/bom/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-bom</artifactId>
-  <version>3.18.0-rc-2</version>
+  <version>3.18.0</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [BOM]</name>
diff --git a/java/core/pom.xml b/java/core/pom.xml
index 3e64394753..bf185b0564 100644
--- a/java/core/pom.xml
+++ b/java/core/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.18.0-rc-2</version>
+    <version>3.18.0</version>
   </parent>
 
   <artifactId>protobuf-java</artifactId>
diff --git a/java/kotlin-lite/pom.xml b/java/kotlin-lite/pom.xml
index 6afadc1084..d6342ee088 100644
--- a/java/kotlin-lite/pom.xml
+++ b/java/kotlin-lite/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.18.0-rc-2</version>
+    <version>3.18.0</version>
   </parent>
 
   <artifactId>protobuf-kotlin-lite</artifactId>
diff --git a/java/kotlin/pom.xml b/java/kotlin/pom.xml
index d2c077bb45..263be68d34 100644
--- a/java/kotlin/pom.xml
+++ b/java/kotlin/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.18.0-rc-2</version>
+    <version>3.18.0</version>
   </parent>
 
   <artifactId>protobuf-kotlin</artifactId>
diff --git a/java/lite/pom.xml b/java/lite/pom.xml
index 70ea62c709..e5e60a85dc 100644
--- a/java/lite/pom.xml
+++ b/java/lite/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.18.0-rc-2</version>
+    <version>3.18.0</version>
   </parent>
 
   <artifactId>protobuf-javalite</artifactId>
diff --git a/java/pom.xml b/java/pom.xml
index 1259e90bcc..3ace5c0327 100644
--- a/java/pom.xml
+++ b/java/pom.xml
@@ -4,7 +4,7 @@
 
   <groupId>com.google.protobuf</groupId>
   <artifactId>protobuf-parent</artifactId>
-  <version>3.18.0-rc-2</version>
+  <version>3.18.0</version>
   <packaging>pom</packaging>
 
   <name>Protocol Buffers [Parent]</name>
diff --git a/java/util/pom.xml b/java/util/pom.xml
index 1148070e32..7266f8f87c 100644
--- a/java/util/pom.xml
+++ b/java/util/pom.xml
@@ -4,7 +4,7 @@
   <parent>
     <groupId>com.google.protobuf</groupId>
     <artifactId>protobuf-parent</artifactId>
-    <version>3.18.0-rc-2</version>
+    <version>3.18.0</version>
   </parent>
 
   <artifactId>protobuf-java-util</artifactId>
diff --git a/js/package.json b/js/package.json
index 7478b73370..10426a3528 100644
--- a/js/package.json
+++ b/js/package.json
@@ -1,6 +1,6 @@
 {
   "name": "google-protobuf",
-  "version": "3.18.0-rc.2",
+  "version": "3.18.0",
   "description": "Protocol Buffers for JavaScript",
   "main": "google-protobuf.js",
   "files": [
diff --git a/php/ext/google/protobuf/package.xml b/php/ext/google/protobuf/package.xml
index c3e7eddf54..7cf1a817a8 100644
--- a/php/ext/google/protobuf/package.xml
+++ b/php/ext/google/protobuf/package.xml
@@ -10,19 +10,19 @@
   <email>protobuf-opensource@google.com</email>
   <active>yes</active>
  </lead>
- <date>2021-08-27</date>
- <time>14:37:43</time>
+ <date>2021-09-13</date>
+ <time>11:30:58</time>
  <version>
-  <release>3.18.0RC2</release>
+  <release>3.18.0</release>
   <api>3.18.0</api>
  </version>
  <stability>
-  <release>beta</release>
-  <api>beta</api>
+  <release>stable</release>
+  <api>stable</api>
  </stability>
  <license uri="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</license>
  <notes>
- * No new changes in 3.17.2
+ * No new changes in 3.18.0
  </notes>
  <contents>
   <dir baseinstalldir="/" name="/">
@@ -1068,5 +1068,20 @@ G  A release.
    <notes>
    </notes>
   </release>
+  <release>
+   <version>
+    <release>3.18.0</release>
+    <api>3.18.0</api>
+   </version>
+   <stability>
+    <release>stable</release>
+    <api>stable</api>
+   </stability>
+   <date>2021-09-13</date>
+   <time>11:30:58</time>
+   <license uri="https://opensource.org/licenses/BSD-3-Clause">3-Clause BSD License</license>
+   <notes>
+   </notes>
+  </release>
  </changelog>
 </package>
diff --git a/php/ext/google/protobuf/protobuf.h b/php/ext/google/protobuf/protobuf.h
index 983b9b3ef6..dbebca3883 100644
--- a/php/ext/google/protobuf/protobuf.h
+++ b/php/ext/google/protobuf/protobuf.h
@@ -91,7 +91,7 @@ ZEND_BEGIN_ARG_INFO_EX(arginfo_setter, 0, 0, 1)
   ZEND_ARG_INFO(0, value)
 ZEND_END_ARG_INFO()
 
-#define PHP_PROTOBUF_VERSION "3.18.0RC2"
+#define PHP_PROTOBUF_VERSION "3.18.0"
 
 // ptr -> PHP object cache. This is a weak map that caches lazily-created
 // wrapper objects around upb types:
diff --git a/protobuf_version.bzl b/protobuf_version.bzl
index 68af71e850..f3ef08340d 100644
--- a/protobuf_version.bzl
+++ b/protobuf_version.bzl
@@ -1 +1 @@
-PROTOBUF_VERSION = '3.18.0-rc-2'
+PROTOBUF_VERSION = '3.18.0'
diff --git a/protoc-artifacts/pom.xml b/protoc-artifacts/pom.xml
index 758fdb8aae..93b118baaf 100644
--- a/protoc-artifacts/pom.xml
+++ b/protoc-artifacts/pom.xml
@@ -8,7 +8,7 @@
   </parent>
   <groupId>com.google.protobuf</groupId>
   <artifactId>protoc</artifactId>
-  <version>3.18.0-rc-2</version>
+  <version>3.18.0</version>
   <packaging>pom</packaging>
   <name>Protobuf Compiler</name>
   <description>
diff --git a/python/google/protobuf/__init__.py b/python/google/protobuf/__init__.py
index b733b764fb..cb4740412a 100644
--- a/python/google/protobuf/__init__.py
+++ b/python/google/protobuf/__init__.py
@@ -30,4 +30,4 @@
 
 # Copyright 2007 Google Inc. All Rights Reserved.
 
-__version__ = '3.18.0rc2'
+__version__ = '3.18.0'
diff --git a/ruby/google-protobuf.gemspec b/ruby/google-protobuf.gemspec
index ec8e455823..3647d8bb6b 100644
--- a/ruby/google-protobuf.gemspec
+++ b/ruby/google-protobuf.gemspec
@@ -1,6 +1,6 @@
 Gem::Specification.new do |s|
   s.name        = "google-protobuf"
-  s.version     = "3.18.0.rc.2"
+  s.version     = "3.18.0"
   git_tag       = "v#{s.version.to_s.sub('.rc.', '-rc')}" # Converts X.Y.Z.rc.N to vX.Y.Z-rcN, used for the git tag
   s.licenses    = ["BSD-3-Clause"]
   s.summary     = "Protocol Buffers"
diff --git a/src/google/protobuf/port_def.inc b/src/google/protobuf/port_def.inc
index 68966477ef..c440a81001 100644
--- a/src/google/protobuf/port_def.inc
+++ b/src/google/protobuf/port_def.inc
@@ -168,7 +168,7 @@
 #ifdef PROTOBUF_VERSION_SUFFIX
 #error PROTOBUF_VERSION_SUFFIX was previously defined
 #endif
-#define PROTOBUF_VERSION_SUFFIX "-rc2"
+#define PROTOBUF_VERSION_SUFFIX ""
 
 #if defined(PROTOBUF_NAMESPACE) || defined(PROTOBUF_NAMESPACE_ID)
 #error PROTOBUF_NAMESPACE or PROTOBUF_NAMESPACE_ID was previously defined
diff --git a/src/google/protobuf/stubs/common.h b/src/google/protobuf/stubs/common.h
index fe6a20375b..ef26f40aae 100644
--- a/src/google/protobuf/stubs/common.h
+++ b/src/google/protobuf/stubs/common.h
@@ -85,7 +85,7 @@ namespace internal {
 #define GOOGLE_PROTOBUF_VERSION 3018000
 
 // A suffix string for alpha, beta or rc releases. Empty for stable releases.
-#define GOOGLE_PROTOBUF_VERSION_SUFFIX "-rc2"
+#define GOOGLE_PROTOBUF_VERSION_SUFFIX ""
 
 // The minimum header version which works with the current version of
 // the library.  This constant should only be used by protoc's C++ code