diff --git a/_data/scala-releases.yml b/_data/scala-releases.yml
index b7c41cd21..497af9ee0 100644
--- a/_data/scala-releases.yml
+++ b/_data/scala-releases.yml
@@ -12,8 +12,8 @@
   release_date: November 24, 2025
 - category: maintenance_version
   title: Latest 2.12.x maintenance release
-  version: 2.12.20
-  release_date: September 4, 2024
+  version: 2.12.21
+  release_date: December 11, 2025
 - category: maintenance_version
   title: Last 2.11.x maintenance release
   version: 2.11.12
diff --git a/_downloads/2025-12-11-2.12.21.md b/_downloads/2025-12-11-2.12.21.md
new file mode 100644
index 000000000..39802670f
--- /dev/null
+++ b/_downloads/2025-12-11-2.12.21.md
@@ -0,0 +1,21 @@
+---
+title: Scala 2.12.21
+start: 11 December 2025
+layout: downloadpage
+release_version: 2.12.21
+release_date: "December 11, 2025"
+show_resources: "true"
+permalink: /download/2.12.21.html
+requirements: "This Scala software distribution can be installed on any Unix-like or Windows system. It requires Java 8 or later, available <a href='https://www.java.com/'>here</a>."
+api_docs: https://www.scala-lang.org/api/2.12.21/
+resources: [
+  ["-main-unixsys", "scala-2.12.21.tgz", "https://github.com/scala/scala/releases/download/v2.12.21/scala-2.12.21.tgz", "Mac OS X, Unix, Cygwin", "20.09M"],
+  ["-main-windows", "scala-2.12.21.msi", "https://github.com/scala/scala/releases/download/v2.12.21/scala-2.12.21.msi", "Windows (msi installer)", "126.72M"],
+  ["-non-main-sys", "scala-2.12.21.zip", "https://github.com/scala/scala/releases/download/v2.12.21/scala-2.12.21.zip", "Windows", "20.13M"],
+  ["-non-main-sys", "scala-2.12.21.deb", "https://github.com/scala/scala/releases/download/v2.12.21/scala-2.12.21.deb", "Debian", "634.20M"],
+  ["-non-main-sys", "scala-2.12.21.rpm", "https://github.com/scala/scala/releases/download/v2.12.21/scala-2.12.21.rpm", "RPM package", "127.07M"],
+  ["-non-main-sys", "scala-docs-2.12.21.txz", "https://github.com/scala/scala/releases/download/v2.12.21/scala-docs-2.12.21.txz", "API docs", "54.83M"],
+  ["-non-main-sys", "scala-docs-2.12.21.zip", "https://github.com/scala/scala/releases/download/v2.12.21/scala-docs-2.12.21.zip", "API docs", "109.82M"],
+  ["-non-main-sys", "scala-sources-2.12.21.tar.gz", "https://github.com/scala/scala/archive/v2.12.21.tar.gz", "Sources", "6.6M"]
+]
+---
diff --git a/_posts/2025-12-11-release-notes-2.12.21.md b/_posts/2025-12-11-release-notes-2.12.21.md
new file mode 100644
index 000000000..626f8bcbb
--- /dev/null
+++ b/_posts/2025-12-11-release-notes-2.12.21.md
@@ -0,0 +1,10 @@
+---
+category: announcement
+permalink: /news/2.12.21/
+title: "Scala 2.12.21 is now available!"
+---
+[Scala 2.12.21](https://github.com/scala/scala/releases/tag/v2.12.21) is now available!
+
+This release is compatible with JDK 25 LTS and also introduces preliminary support for JDK 26.
+
+For all the details, refer to the [release notes](https://github.com/scala/scala/releases/tag/v2.12.21) on GitHub.