diff --git a/.github/workflows/coding-standards.yml b/.github/workflows/coding-standards.yml
index 41faf379ee..95e2af0172 100644
--- a/.github/workflows/coding-standards.yml
+++ b/.github/workflows/coding-standards.yml
@@ -5,7 +5,6 @@ on:
   # PHPCS checking was introduced in WordPress 5.1.
   push:
     branches:
-      - master
       - trunk
       - '3.[89]'
       - '[4-9].[0-9]'
@@ -14,7 +13,6 @@ on:
       - '[4-9].[0-9]*'
   pull_request:
     branches:
-      - master
       - trunk
       - '3.[89]'
       - '[4-9].[0-9]'
@@ -149,7 +147,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ phpcs, jshint ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/end-to-end-tests.yml b/.github/workflows/end-to-end-tests.yml
index 6bcaa9a3ff..4b2f9f1c44 100644
--- a/.github/workflows/end-to-end-tests.yml
+++ b/.github/workflows/end-to-end-tests.yml
@@ -4,7 +4,6 @@ on:
   # The end to end test suite was introduced in WordPress 5.3.
   push:
     branches:
-      - master
       - trunk
       - '5.[3-9]'
       - '[6-9].[0-9]'
@@ -13,7 +12,6 @@ on:
       - '[6-9].[0-9]*'
   pull_request:
     branches:
-      - master
       - trunk
       - '5.[3-9]'
       - '[6-9].[0-9]'
@@ -119,7 +117,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ e2e-tests ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/javascript-tests.yml b/.github/workflows/javascript-tests.yml
index 4c0c6e17e1..451eee86cb 100644
--- a/.github/workflows/javascript-tests.yml
+++ b/.github/workflows/javascript-tests.yml
@@ -4,7 +4,6 @@ on:
   # JavaScript testing was introduced in WordPress 3.8.
   push:
     branches:
-      - master
       - trunk
       - '3.[89]'
       - '[4-9].[0-9]'
@@ -13,7 +12,6 @@ on:
       - '[4-9].[0-9]*'
   pull_request:
     branches:
-      - master
       - trunk
       - '3.[89]'
       - '[4-9].[0-9]'
@@ -88,7 +86,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ test-js ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/php-compatibility.yml b/.github/workflows/php-compatibility.yml
index de89b79a3d..82202829ef 100644
--- a/.github/workflows/php-compatibility.yml
+++ b/.github/workflows/php-compatibility.yml
@@ -4,7 +4,6 @@ on:
   # PHP compatibility testing was introduced in WordPress 5.5.
   push:
     branches:
-      - master
       - trunk
       - '5.[5-9]'
       - '[6-9].[0-9]'
@@ -13,7 +12,6 @@ on:
       - '[6-9].[0-9]*'
   pull_request:
     branches:
-      - master
       - trunk
       - '5.[5-9]'
       - '[6-9].[0-9]'
@@ -90,7 +88,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ php-compatibility ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/phpunit-tests.yml b/.github/workflows/phpunit-tests.yml
index b6ce31b99b..aa5037f10c 100644
--- a/.github/workflows/phpunit-tests.yml
+++ b/.github/workflows/phpunit-tests.yml
@@ -3,7 +3,6 @@ name: PHPUnit Tests
 on:
   push:
     branches:
-      - master
       - trunk
       - '3.[7-9]'
       - '[4-9].[0-9]'
@@ -12,7 +11,6 @@ on:
       - '[4-9].[0-9]*'
   pull_request:
     branches:
-      - master
       - trunk
       - '3.[7-9]'
       - '[4-9].[0-9]'
@@ -231,21 +229,21 @@ jobs:
         run: git diff --exit-code
 
       - name: Checkout the WordPress Test Reporter
-        if: ${{ github.repository == 'WordPress/wordpress-develop' && github.ref == 'refs/heads/master' && matrix.report }}
+        if: ${{ github.repository == 'WordPress/wordpress-develop' && github.ref == 'refs/heads/trunk' && matrix.report }}
         uses: actions/checkout@5a4ac9002d0be2fb38bd78e4b4dbde5606d7042f # v2.3.4
         with:
           repository: 'WordPress/phpunit-test-runner'
           path: 'test-runner'
 
       - name: Submit test results to the WordPress.org host test results
-        if: ${{ github.repository == 'WordPress/wordpress-develop' && github.ref == 'refs/heads/master' && matrix.report }}
+        if: ${{ github.repository == 'WordPress/wordpress-develop' && github.ref == 'refs/heads/trunk' && matrix.report }}
         env:
           WPT_REPORT_API_KEY: "${{ secrets.WPT_REPORT_API_KEY }}"
         run: docker-compose run --rm -e WPT_REPORT_API_KEY -e WPT_PREPARE_DIR=/var/www -e WPT_TEST_DIR=/var/www php php test-runner/report.php
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ test-php ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/test-coverage.yml b/.github/workflows/test-coverage.yml
index b11ae0348e..afd042bfd1 100644
--- a/.github/workflows/test-coverage.yml
+++ b/.github/workflows/test-coverage.yml
@@ -4,7 +4,6 @@ on:
   # Verify
   push:
     branches:
-      - master
       - trunk
     paths:
       - '.github/workflows/test-coverage.yml'
@@ -171,7 +170,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ test-coverage-report ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/test-npm.yml b/.github/workflows/test-npm.yml
index 0b49e9ab7c..3073f56809 100644
--- a/.github/workflows/test-npm.yml
+++ b/.github/workflows/test-npm.yml
@@ -3,13 +3,11 @@ name: Test NPM
 on:
   push:
     branches:
-      - master
       - trunk
       - '3.[7-9]'
       - '[4-9].[0-9]'
   pull_request:
     branches:
-      - master
       - trunk
       - '3.[7-9]'
       - '[4-9].[0-9]'
@@ -157,7 +155,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ test-npm, test-npm-macos ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with:
diff --git a/.github/workflows/test-old-branches.yml b/.github/workflows/test-old-branches.yml
index 1d0bc59a7e..f1fa017f84 100644
--- a/.github/workflows/test-old-branches.yml
+++ b/.github/workflows/test-old-branches.yml
@@ -4,7 +4,6 @@ on:
   # Verify the workflow is successful when this file is updated.
   push:
     branches:
-      - master
       - trunk
     paths:
       - '.github/workflows/test-old-branches.yml'
@@ -72,7 +71,7 @@ jobs:
 
   slack-notifications:
     name: Slack Notifications
-    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@master
+    uses: WordPress/wordpress-develop/.github/workflows/slack-notifications.yml@trunk
     needs: [ dispatch-workflows-for-old-branches ]
     if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
     with: