diff --git a/.github/workflows/javascript-type-checking.yml b/.github/workflows/javascript-type-checking.yml
new file mode 100644
index 0000000000000..2cafb4c8d04fd
--- /dev/null
+++ b/.github/workflows/javascript-type-checking.yml
@@ -0,0 +1,100 @@
+name: JavaScript Type Checking
+
+on:
+  # JavaScript type checking was introduced in 7.0.0.
+  push:
+    branches:
+      - trunk
+      - '[7-9].[0-9]'
+    tags:
+      - '[7-9].[0-9]'
+      - '[7-9]+.[0-9].[0-9]+'
+  pull_request:
+    branches:
+      - trunk
+      - '[7-9].[0-9]'
+    paths:
+      # This workflow only scans JavaScript files.
+      - '**.js'
+      - '**.ts'
+      - '**.tsx'
+      # These files configure npm. Changes could affect the outcome.
+      - 'package*.json'
+      - '.nvmrc'
+      # This file configures TypeScript. Changes could affect the outcome.
+      - 'tsconfig.json'
+      # This directory contains TypeScript definitions. Changes could affect the outcome.
+      - 'typings/**'
+      # Confirm any changes to relevant workflow files.
+      - '.github/workflows/javascript-type-checking.yml'
+      - '.github/workflows/reusable-javascript-type-checking.yml'
+  workflow_dispatch:
+
+# Cancels all previous workflow runs for pull requests that have not completed.
+concurrency:
+  # The concurrency group contains the workflow name and the branch name for pull requests
+  # or the commit hash for any other events.
+  group: ${{ github.workflow }}-${{ github.event_name == 'pull_request' && github.head_ref || github.sha }}
+  cancel-in-progress: true
+
+# Disable permissions for all available scopes by default.
+# Any needed permissions should be configured at the job level.
+permissions: {}
+
+jobs:
+  # Runs JavaScript type checking.
+  typecheck:
+    name: JavaScript type checking
+    uses: ./.github/workflows/reusable-javascript-type-checking.yml
+    permissions:
+      contents: read
+    if: ${{ github.repository == 'WordPress/wordpress-develop' || ( github.event_name == 'pull_request' && github.actor != 'dependabot[bot]' ) }}
+
+  slack-notifications:
+    name: Slack Notifications
+    uses: ./.github/workflows/slack-notifications.yml
+    permissions:
+      actions: read
+      contents: read
+    needs: [ typecheck ]
+    if: ${{ github.repository == 'WordPress/wordpress-develop' && github.event_name != 'pull_request' && always() }}
+    with:
+      calling_status: ${{ contains( needs.*.result, 'cancelled' ) && 'cancelled' || contains( needs.*.result, 'failure' ) && 'failure' || 'success' }}
+    secrets:
+      SLACK_GHA_SUCCESS_WEBHOOK: ${{ secrets.SLACK_GHA_SUCCESS_WEBHOOK }}
+      SLACK_GHA_CANCELLED_WEBHOOK: ${{ secrets.SLACK_GHA_CANCELLED_WEBHOOK }}
+      SLACK_GHA_FIXED_WEBHOOK: ${{ secrets.SLACK_GHA_FIXED_WEBHOOK }}
+      SLACK_GHA_FAILURE_WEBHOOK: ${{ secrets.SLACK_GHA_FAILURE_WEBHOOK }}
+
+  failed-workflow:
+    name: Failed workflow tasks
+    runs-on: ubuntu-24.04
+    permissions:
+      actions: write
+    needs: [ slack-notifications ]
+    if: |
+      always() &&
+      github.repository == 'WordPress/wordpress-develop' &&
+      github.event_name != 'pull_request' &&
+      github.run_attempt < 2 &&
+      (
+        contains( needs.*.result, 'cancelled' ) ||
+        contains( needs.*.result, 'failure' )
+      )
+
+    steps:
+      - name: Dispatch workflow run
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
+        with:
+          retries: 2
+          retry-exempt-status-codes: 418
+          script: |
+            github.rest.actions.createWorkflowDispatch({
+              owner: context.repo.owner,
+              repo: context.repo.repo,
+              workflow_id: 'failed-workflow.yml',
+              ref: 'trunk',
+              inputs: {
+                run_id: `${context.runId}`,
+              }
+            });
diff --git a/.github/workflows/phpstan-static-analysis.yml b/.github/workflows/phpstan-static-analysis.yml
index 9bb12e40927e2..85f492e5f13af 100644
--- a/.github/workflows/phpstan-static-analysis.yml
+++ b/.github/workflows/phpstan-static-analysis.yml
@@ -81,7 +81,7 @@ jobs:
 
     steps:
       - name: Dispatch workflow run
-        uses: actions/github-script@60a0d83039c74a4aee543508d2ffcb1c3799cdea # v7.0.1
+        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
         with:
           retries: 2
           retry-exempt-status-codes: 418
diff --git a/.github/workflows/reusable-javascript-type-checking.yml b/.github/workflows/reusable-javascript-type-checking.yml
new file mode 100644
index 0000000000000..3737bba6abb74
--- /dev/null
+++ b/.github/workflows/reusable-javascript-type-checking.yml
@@ -0,0 +1,76 @@
+##
+# A reusable workflow that runs JavaScript Type Checking.
+##
+name: JavaScript Type Checking
+
+on:
+  workflow_call:
+
+# Disable permissions for all available scopes by default.
+# Any needed permissions should be configured at the job level.
+permissions: {}
+
+jobs:
+  # Runs JavaScript type checking.
+  #
+  # Violations are reported inline with annotations.
+  #
+  # Performs the following steps:
+  # - Checks out the repository.
+  # - Sets up Node.js.
+  # - Logs debug information.
+  # - Installs npm dependencies.
+  # - Configures caching for TypeScript build info.
+  # - Runs JavaScript type checking.
+  # - Saves the TypeScript build info.
+  # - Ensures version-controlled files are not modified or deleted.
+  typecheck:
+    name: Run JavaScript type checking
+    runs-on: ubuntu-24.04
+    permissions:
+      contents: read
+    timeout-minutes: 10
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
+        with:
+          show-progress: ${{ runner.debug == '1' && 'true' || 'false' }}
+          persist-credentials: false
+
+      - name: Set up Node.js
+        uses: actions/setup-node@2028fbc5c25fe9cf00d9f06a71cc4710d4507903 # v6.0.0
+        with:
+          node-version-file: '.nvmrc'
+          cache: npm
+
+      - name: Log debug information
+        run: |
+          npm --version
+          node --version
+
+      - name: Install npm dependencies
+        run: npm ci --ignore-scripts
+
+      - name: Cache TypeScript build info
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        with:
+          path: |
+            *.tsbuildinfo
+          key: "ts-build-info-${{ github.run_id }}"
+          restore-keys: |
+            ts-build-info-
+
+      - name: Run JavaScript type checking
+        run: npm run typecheck:js
+
+      - name: "Save result cache"
+        uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
+        if: ${{ !cancelled() }}
+        with:
+          path: |
+            *.tsbuildinfo
+          key: "ts-build-info-${{ github.run_id }}"
+
+      - name: Ensure version-controlled files are not modified or deleted
+        run: git diff --exit-code
diff --git a/Gruntfile.js b/Gruntfile.js
index 2fe7dac819c6c..b5c69553f3f0d 100644
--- a/Gruntfile.js
+++ b/Gruntfile.js
@@ -1556,6 +1556,7 @@ module.exports = function(grunt) {
 	grunt.registerTask( 'precommit:js', [
 		'webpack:prod',
 		'jshint:corejs',
+		'typecheck:js',
 		'uglify:imgareaselect',
 		'uglify:jqueryform',
 		'uglify:moment',
@@ -2009,6 +2010,18 @@ module.exports = function(grunt) {
 
 	grunt.registerTask( 'test', 'Runs all QUnit and PHPUnit tasks.', ['qunit:compiled', 'phpunit'] );
 
+	grunt.registerTask( 'typecheck:js', 'Runs TypeScript type checking.', function() {
+		var done = this.async();
+
+		grunt.util.spawn( {
+			cmd: 'npm',
+			args: [ 'run', 'typecheck:js' ],
+			opts: { stdio: 'inherit' }
+		}, function( error ) {
+			done( ! error );
+		} );
+	} );
+
 	grunt.registerTask( 'phpstan', 'Runs PHPStan on the entire codebase.', function() {
 		var done = this.async();