diff --git a/lib/client-assets.php b/lib/client-assets.php
index 62689eb9772190..db9d6af01680aa 100644
--- a/lib/client-assets.php
+++ b/lib/client-assets.php
@@ -369,6 +369,9 @@ function gutenberg_enqueue_stored_styles( $options = array() ) {
 function gutenberg_register_vendor_scripts( $scripts ) {
 	$extension = SCRIPT_DEBUG ? '.js' : '.min.js';
 
+	// Bust browser caches when the bundled React version changes (see build/constants.php, generated from package.json).
+	$react_vendor_version = defined( 'GUTENBERG_REACT_VENDOR_VERSION' ) ? GUTENBERG_REACT_VENDOR_VERSION : '18.3.1';
+
 	gutenberg_override_script(
 		$scripts,
 		'react',
@@ -376,14 +379,14 @@ function gutenberg_register_vendor_scripts( $scripts ) {
 		// WordPress Core in `wp_register_development_scripts` sets `wp-react-refresh-entry` as a dependency to `react` when `SCRIPT_DEBUG` is true.
 		// We need to preserve that here.
 		SCRIPT_DEBUG ? array( 'wp-react-refresh-entry', 'wp-polyfill' ) : array( 'wp-polyfill' ),
-		'18'
+		$react_vendor_version
 	);
 	gutenberg_override_script(
 		$scripts,
 		'react-dom',
 		gutenberg_url( 'build/scripts/vendors/react-dom' . $extension ),
 		array( 'react' ),
-		'18'
+		$react_vendor_version
 	);
 
 	gutenberg_override_script(
@@ -391,7 +394,7 @@ function gutenberg_register_vendor_scripts( $scripts ) {
 		'react-jsx-runtime',
 		gutenberg_url( 'build/scripts/vendors/react-jsx-runtime' . $extension ),
 		array( 'react' ),
-		'18'
+		$react_vendor_version
 	);
 }
 add_action( 'wp_default_scripts', 'gutenberg_register_vendor_scripts' );
diff --git a/lib/load.php b/lib/load.php
index 88ef3408da2c90..53d128d2120eba 100644
--- a/lib/load.php
+++ b/lib/load.php
@@ -26,6 +26,10 @@
 if ( file_exists( $constants_file ) && ! defined( 'GUTENBERG_VERSION' ) ) {
 	$build_constants = require_once $constants_file;
 	define( 'GUTENBERG_VERSION', $build_constants['version'] );
+	$react_vendor_version = $build_constants['react_version'] ?? '';
+	if ( $react_vendor_version && ! defined( 'GUTENBERG_REACT_VENDOR_VERSION' ) ) {
+		define( 'GUTENBERG_REACT_VENDOR_VERSION', $react_vendor_version );
+	}
 }
 
 /**
diff --git a/packages/wp-build/lib/php-generator.mjs b/packages/wp-build/lib/php-generator.mjs
index 0a781cdffa9259..4da7cd7f7e7739 100644
--- a/packages/wp-build/lib/php-generator.mjs
+++ b/packages/wp-build/lib/php-generator.mjs
@@ -17,7 +17,7 @@ const __dirname = path.dirname( fileURLToPath( import.meta.url ) );
  *
  * @param {string} rootDir           Root directory path.
  * @param {string} baseUrlExpression PHP expression for base URL (e.g. "includes_url( 'build' )").
- * @return {Promise<Record<string, string>>} Replacements object with {{PREFIX}}, {{VERSION}}, {{BASE_URL}}.
+ * @return {Promise<Record<string, string>>} Replacements object with {{PREFIX}}, {{VERSION}}, {{BASE_URL}}, {{REACT_VERSION}}.
  */
 export async function getPhpReplacements( rootDir, baseUrlExpression ) {
 	const rootPackageJson = getPackageInfoFromFile(
@@ -31,10 +31,17 @@ export async function getPhpReplacements( rootDir, baseUrlExpression ) {
 	const name = rootPackageJson.wpPlugin?.name || 'gutenberg';
 	const version = rootPackageJson.version;
 
+	// Used to cache-bust vendor React bundles when the React pin changes independently of WordPress.
+	const reactVersion =
+		rootPackageJson.devDependencies?.react ??
+		rootPackageJson.dependencies?.react ??
+		'';
+
 	return {
 		'{{PREFIX}}': name,
 		'{{VERSION}}': version,
 		'{{BASE_URL}}': baseUrlExpression,
+		'{{REACT_VERSION}}': reactVersion,
 	};
 }
 
diff --git a/packages/wp-build/templates/constants.php.template b/packages/wp-build/templates/constants.php.template
index 8136230c9f499a..018ce317f508a5 100644
--- a/packages/wp-build/templates/constants.php.template
+++ b/packages/wp-build/templates/constants.php.template
@@ -11,4 +11,5 @@
 return array(
 	'version' => '{{VERSION}}',
 	'build_url' => {{BASE_URL}},
+	'react_version' => '{{REACT_VERSION}}',
 );