diff --git a/CHANGELOG.md b/CHANGELOG.md
index 537eec7fc..0dc6b74ff 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,6 @@
 # CodeQL Action and CodeQL Runner Changelog
 
-## [UNRELEASED]
+## 1.0.0 - 31 May 2021
 
 - Add this changelog file. [#507](https://github.com/github/codeql-action/pull/507)
 - Improve grouping of analysis logs. Add a new log group containing a summary of metrics and diagnostics, if they were produced by CodeQL builtin queries. [#515](https://github.com/github/codeql-action/pull/515)