diff --git a/CHANGELOG.md b/CHANGELOG.md
index 1d2778139204..3d9867ef29c4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,24 @@
 # Changelog
 
-## [v4.5.4](https://github.com/codeigniter4/CodeIgniter4/tree/v4.5.3) (2024-07-27)
+## [v4.5.5](https://github.com/codeigniter4/CodeIgniter4/tree/v4.5.5) (2024-09-07)
+[Full Changelog](https://github.com/codeigniter4/CodeIgniter4/compare/v4.5.4...v4.5.5)
+
+### Fixed Bugs
+
+* fix: Validation rule `differs`/`matches` with dot array by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9103
+* fix: update preload.php by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9111
+* fix: [Validation] TypeError when using numeric field names by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9142
+* fix: `auto_link()` regexp by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9169
+
+### Refactoring
+
+* refactor: reduce_multiples() and fix user guide by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9099
+* refactor: enable AddMethodCallBasedStrictParamTypeRector by @samsonasik in https://github.com/codeigniter4/CodeIgniter4/pull/9156
+* refactor: BaseBuilder by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9157
+* refactor: improve error message for missing PHP DB extensions by @kenjis in https://github.com/codeigniter4/CodeIgniter4/pull/9160
+* refactor: fix typo in BaseConnection.php by @ThomasMeschke in https://github.com/codeigniter4/CodeIgniter4/pull/9170
+
+## [v4.5.4](https://github.com/codeigniter4/CodeIgniter4/tree/v4.5.4) (2024-07-27)
 [Full Changelog](https://github.com/codeigniter4/CodeIgniter4/compare/v4.5.3...v4.5.4)
 
 ### Fixed Bugs
diff --git a/phpdoc.dist.xml b/phpdoc.dist.xml
index e67b1b29ed55..7f13b0e78cff 100644
--- a/phpdoc.dist.xml
+++ b/phpdoc.dist.xml
@@ -10,7 +10,7 @@
         <output>api/build/</output>
         <cache>api/cache/</cache>
     </paths>
-    <version number="4.5.4">
+    <version number="4.5.5">
         <api format="php">
             <source dsn=".">
                 <path>system</path>
diff --git a/system/CodeIgniter.php b/system/CodeIgniter.php
index bcfb7bd67976..48fbc9d77e23 100644
--- a/system/CodeIgniter.php
+++ b/system/CodeIgniter.php
@@ -56,7 +56,7 @@ class CodeIgniter
     /**
      * The current version of CodeIgniter Framework
      */
-    public const CI_VERSION = '4.5.4';
+    public const CI_VERSION = '4.5.5';
 
     /**
      * App startup time.
diff --git a/user_guide_src/source/changelogs/v4.5.5.rst b/user_guide_src/source/changelogs/v4.5.5.rst
index aaea324399af..66d6d2a6e603 100644
--- a/user_guide_src/source/changelogs/v4.5.5.rst
+++ b/user_guide_src/source/changelogs/v4.5.5.rst
@@ -2,7 +2,7 @@
 Version 4.5.5
 #############
 
-Release Date: Unreleased
+Release Date: September 7, 2024
 
 **4.5.5 release of CodeIgniter4**
 
@@ -10,22 +10,6 @@ Release Date: Unreleased
     :local:
     :depth: 3
 
-********
-BREAKING
-********
-
-***************
-Message Changes
-***************
-
-*******
-Changes
-*******
-
-************
-Deprecations
-************
-
 **********
 Bugs Fixed
 **********
diff --git a/user_guide_src/source/conf.py b/user_guide_src/source/conf.py
index 431dc6d57bd9..fea4122185a2 100644
--- a/user_guide_src/source/conf.py
+++ b/user_guide_src/source/conf.py
@@ -26,7 +26,7 @@
 version = '4.5'
 
 # The full version, including alpha/beta/rc tags.
-release = '4.5.4'
+release = '4.5.5'
 
 # -- General configuration ---------------------------------------------------
 
diff --git a/user_guide_src/source/installation/upgrade_455.rst b/user_guide_src/source/installation/upgrade_455.rst
index bbff938631c5..74d2bfbf7b2d 100644
--- a/user_guide_src/source/installation/upgrade_455.rst
+++ b/user_guide_src/source/installation/upgrade_455.rst
@@ -12,18 +12,6 @@ Please refer to the upgrade instructions corresponding to your installation meth
     :local:
     :depth: 2
 
-**********************
-Mandatory File Changes
-**********************
-
-****************
-Breaking Changes
-****************
-
-*********************
-Breaking Enhancements
-*********************
-
 *************
 Project Files
 *************
@@ -44,7 +32,7 @@ and it is recommended that you merge the updated versions with your application:
 Config
 ------
 
-- @TODO
+- composer.json
 
 All Changes
 ===========
@@ -52,4 +40,4 @@ All Changes
 This is a list of all files in the **project space** that received changes;
 many will be simple comments or formatting that have no effect on the runtime:
 
-- @TODO
+- composer.json