diff --git a/admin/class-convertkit-admin-legacy-resource-notice.php b/admin/class-convertkit-admin-legacy-resource-notice.php
new file mode 100644
index 000000000..259555f0a
--- /dev/null
+++ b/admin/class-convertkit-admin-legacy-resource-notice.php
@@ -0,0 +1,265 @@
+<?php
+/**
+ * ConvertKit Admin Legacy Resource Notice class.
+ *
+ * @package ConvertKit
+ * @author ConvertKit
+ */
+
+/**
+ * Renders a non-dismissible warning notice in the WordPress admin when a
+ * Post or Page references a Legacy Form or Legacy Landing Page.
+ *
+ * @since   3.3.7
+ */
+class ConvertKit_Admin_Legacy_Resource_Notice {
+
+	/**
+	 * The Gutenberg notice ID, used both as the deduplication key and as
+	 * the JS-side selector when tests need to locate the notice.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @var     string
+	 */
+	const GUTENBERG_NOTICE_ID = 'convertkit-legacy-resource-warning';
+
+	/**
+	 * Registers action and filter hooks.
+	 *
+	 * @since   3.3.7
+	 */
+	public function __construct() {
+
+		add_action( 'admin_notices', array( $this, 'output_classic_editor_notice' ) );
+		add_action( 'enqueue_block_editor_assets', array( $this, 'enqueue_gutenberg_notice' ) );
+
+	}
+
+	/**
+	 * Outputs the consolidated warning notice on the classic editor's post
+	 * edit screen. Non-dismissible (no `is-dismissible` class).
+	 *
+	 * @since   3.3.7
+	 */
+	public function output_classic_editor_notice() {
+
+		// Bail if not on a post edit screen.
+		if ( convertkit_get_current_screen( 'base' ) !== 'post' ) {
+			return;
+		}
+		if ( ! in_array( convertkit_get_current_screen( 'post_type' ), convertkit_get_supported_post_types(), true ) ) {
+			return;
+		}
+
+		// Bail if no post ID is found.
+		$post_id = $this->get_current_post_id();
+		if ( ! $post_id ) {
+			return;
+		}
+
+		// Get warnings.
+		$warnings = $this->get_legacy_warnings_for_post_settings( $post_id );
+
+		// Bail if no warnings are found.
+		if ( empty( $warnings ) ) {
+			return;
+		}
+
+		// Output warnings.
+		?>
+		<div class="notice notice-warning">
+			<p>
+				<strong><?php esc_html_e( 'Kit', 'convertkit' ); ?>:</strong>
+				<?php esc_html_e( 'This page uses one or more legacy Kit resources that are no longer offered for new selections. The following continue to work, but we recommend migrating:', 'convertkit' ); ?>
+			</p>
+			<ul>
+				<?php
+				foreach ( $warnings as $warning ) {
+					echo '<li>' . esc_html( $warning ) . '</li>';
+				}
+				?>
+			</ul>
+		</div>
+		<?php
+
+	}
+
+	/**
+	 * Enqueues a small JS handler that renders the same warning inside
+	 * Gutenberg via wp.data.dispatch('core/notices'). Non-dismissible via
+	 * the `isDismissible: false` option.
+	 *
+	 * @since   3.3.7
+	 */
+	public function enqueue_gutenberg_notice() {
+
+		// Bail if not on a post edit screen.
+		if ( convertkit_get_current_screen( 'base' ) !== 'post' ) {
+			return;
+		}
+
+		// Bail if not on a supported post type.
+		if ( ! in_array( convertkit_get_current_screen( 'post_type' ), convertkit_get_supported_post_types(), true ) ) {
+			return;
+		}
+
+		// Bail if no post ID is found.
+		$post_id = $this->get_current_post_id();
+		if ( ! $post_id ) {
+			return;
+		}
+
+		// Get warnings.
+		$warnings = $this->get_legacy_warnings_for_post_settings( $post_id );
+
+		// Bail if no warnings are found.
+		if ( empty( $warnings ) ) {
+			return;
+		}
+
+		// Enqueue script.
+		wp_enqueue_script(
+			'convertkit-admin-legacy-resource-notice',
+			CONVERTKIT_PLUGIN_URL . 'resources/backend/js/legacy-resource-notice.js',
+			array( 'wp-data', 'wp-notices' ),
+			CONVERTKIT_PLUGIN_VERSION,
+			true
+		);
+
+		// Localize script.
+		wp_localize_script(
+			'convertkit-admin-legacy-resource-notice',
+			'convertkit_legacy_resource_notice',
+			array(
+				'id'       => self::GUTENBERG_NOTICE_ID,
+				'intro'    => __( 'Kit: This page uses one or more legacy Kit resources that are no longer offered for new selections. The following continue to work, but we recommend migrating:', 'convertkit' ),
+				'warnings' => $warnings,
+			)
+		);
+
+	}
+
+	/**
+	 * Returns an array of warning strings for the given Post, if the Post settings
+	 * reference a Legacy Form or Legacy Landing Page.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   int $post_id Post ID.
+	 * @return  array
+	 */
+	private function get_legacy_warnings_for_post_settings( $post_id ) {
+
+		// Get Post settings.
+		$convertkit_post = new ConvertKit_Post( $post_id );
+		$settings        = $convertkit_post->get();
+
+		// Get resources.
+		$forms         = new ConvertKit_Resource_Forms();
+		$landing_pages = new ConvertKit_Resource_Landing_Pages();
+
+		// Initialize warnings array.
+		$warnings = array();
+
+		// Form.
+		if ( $forms->is_legacy( $convertkit_post->get_form() ) ) {
+			$warnings[] = sprintf(
+				/* translators: %s: Form name */
+				__( 'Form: %s', 'convertkit' ),
+				$this->get_form_display_name( $convertkit_post->get_form(), $forms )
+			);
+		}
+
+		// Landing Page.
+		if ( $landing_pages->is_legacy( $convertkit_post->get_landing_page() ) ) {
+			$warnings[] = sprintf(
+				/* translators: %s: Landing page name */
+				__( 'Landing Page: %s', 'convertkit' ),
+				$this->get_landing_page_display_name( $convertkit_post->get_landing_page(), $landing_pages )
+			);
+		}
+
+		// Restrict Content.
+		if ( $convertkit_post->get_restrict_content_type() === 'form' && $forms->is_legacy( $convertkit_post->get_restrict_content_id() ) ) {
+			$warnings[] = sprintf(
+				/* translators: %s: Form name */
+				__( 'Member Content: %s', 'convertkit' ),
+				$this->get_form_display_name( $convertkit_post->get_restrict_content_id(), $forms )
+			);
+		}
+
+		return $warnings;
+
+	}
+
+	/**
+	 * Resolves the form ID to a human-readable "Form Name" string, falling
+	 * back to "a Legacy Form" when the resource isn't cached.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   int                       $form_id  Form ID.
+	 * @param   ConvertKit_Resource_Forms $forms  Forms resource class.
+	 * @return  string
+	 */
+	private function get_form_display_name( $form_id, $forms ) {
+
+		$form = $forms->get_by_id( $form_id );
+		if ( $form && ! empty( $form['name'] ) ) {
+			return sanitize_text_field( $form['name'] );
+		}
+
+		return __( 'a Legacy Form', 'convertkit' );
+
+	}
+
+	/**
+	 * Resolves the landing page identifier (numeric ID or URL string) to a
+	 * human-readable "Landing Page Name" string, falling back to
+	 * "a Legacy Landing Page" when the resource isn't cached.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   int|string                        $id_or_url      Landing Page ID or URL.
+	 * @param   ConvertKit_Resource_Landing_Pages $landing_pages  Landing Pages resource class.
+	 * @return  string
+	 */
+	private function get_landing_page_display_name( $id_or_url, $landing_pages ) {
+
+		// URL-string legacy assignments (pre-1.9.6) don't have a cached
+		// resource entry we can look up by ID, so fall back straight away.
+		if ( is_string( $id_or_url ) && strstr( $id_or_url, 'http' ) ) {
+			return __( 'a Legacy Landing Page', 'convertkit' );
+		}
+
+		$landing_page = $landing_pages->get_by_id( (int) $id_or_url );
+		if ( $landing_page && ! empty( $landing_page['name'] ) ) {
+			return sanitize_text_field( $landing_page['name'] );
+		}
+
+		return __( 'a Legacy Landing Page', 'convertkit' );
+
+	}
+
+	/**
+	 * Returns the current post ID being edited, or 0 if not on a post edit
+	 * screen. Reads $_GET['post'] because $post isn't always set in the
+	 * admin_notices / enqueue_block_editor_assets hook contexts.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @return  int
+	 */
+	private function get_current_post_id() {
+
+		// phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		if ( isset( $_GET['post'] ) ) {
+			return absint( $_GET['post'] ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended
+		}
+
+		return 0;
+
+	}
+
+}
diff --git a/includes/class-wp-convertkit.php b/includes/class-wp-convertkit.php
index 371ab59d0..922e466b8 100644
--- a/includes/class-wp-convertkit.php
+++ b/includes/class-wp-convertkit.php
@@ -83,6 +83,7 @@ private function initialize_admin() {
 		$this->classes['admin_cache_plugins']                    = new ConvertKit_Admin_Cache_Plugins();
 		$this->classes['admin_category']                         = new ConvertKit_Admin_Category();
 		$this->classes['admin_landing_page']                     = new ConvertKit_Admin_Landing_Page();
+		$this->classes['admin_legacy_resource_notice']           = new ConvertKit_Admin_Legacy_Resource_Notice();
 		$this->classes['admin_importer_activecampaign']          = new ConvertKit_Admin_Importer_ActiveCampaign();
 		$this->classes['admin_importer_aweber']                  = new ConvertKit_Admin_Importer_AWeber();
 		$this->classes['admin_importer_campaignmonitor']         = new ConvertKit_Admin_Importer_CampaignMonitor();
diff --git a/resources/backend/js/legacy-resource-notice.js b/resources/backend/js/legacy-resource-notice.js
new file mode 100644
index 000000000..cf605d543
--- /dev/null
+++ b/resources/backend/js/legacy-resource-notice.js
@@ -0,0 +1,49 @@
+/**
+ * Renders a non-dismissible warning notice inside Gutenberg
+ * when a post/page references a legacy Kit resource.
+ *
+ * @author ConvertKit
+ * @since  3.3.7
+ */
+
+document.addEventListener('DOMContentLoaded', function () {
+	// Bail if the notice data is not available.
+	if (typeof convertkit_legacy_resource_notice === 'undefined') {
+		return;
+	}
+
+	// Bail if no warnings are found.
+	if (
+		typeof convertkit_legacy_resource_notice.warnings === 'undefined' ||
+		convertkit_legacy_resource_notice.warnings.length === 0
+	) {
+		return;
+	}
+
+	// Bail if Gutenberg is not available.
+	if (
+		typeof wp === 'undefined' ||
+		typeof wp.data === 'undefined' ||
+		typeof wp.data.dispatch !== 'function'
+	) {
+		return;
+	}
+
+	// Build the notice.
+	const message =
+		convertkit_legacy_resource_notice.intro +
+		'\n' +
+		convertkit_legacy_resource_notice.warnings
+			.map(function (warning) {
+				return '- ' + warning;
+			})
+			.join('\n');
+
+	// Create the notice.
+	wp.data
+		.dispatch('core/notices')
+		.createWarningNotice(message, {
+			id: convertkit_legacy_resource_notice.id,
+			isDismissible: false,
+		});
+});
diff --git a/tests/EndToEnd/general/other/BlockEditorLegacyNoticeCest.php b/tests/EndToEnd/general/other/BlockEditorLegacyNoticeCest.php
new file mode 100644
index 000000000..c6d71c988
--- /dev/null
+++ b/tests/EndToEnd/general/other/BlockEditorLegacyNoticeCest.php
@@ -0,0 +1,237 @@
+<?php
+
+namespace Tests\EndToEnd;
+
+use Tests\Support\EndToEndTester;
+
+/**
+ * Tests the non-dismissible legacy-resource warning notice rendered by
+ * ConvertKit_Admin_Legacy_Resource_Notice inside the Gutenberg editor.
+ *
+ * @since   3.3.7
+ */
+class BlockEditorLegacyNoticeCest
+{
+	/**
+	 * The CSS selector matching Gutenberg's snackbar/notice region that
+	 * hosts warning notices dispatched via core/notices.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @var     string
+	 */
+	private $noticeSelector = '.components-notice.is-warning';
+
+	/**
+	 * Run common actions before running the test functions in this class.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function _before(EndToEndTester $I)
+	{
+		$I->activateKitPlugin($I);
+		$I->setupKitPlugin($I);
+		$I->setupKitPluginResources($I);
+	}
+
+	/**
+	 * Test that a page with a legacy Form assignment displays the warning
+	 * notice inside Gutenberg, listing the legacy form by name.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDisplaysForLegacyForm(EndToEndTester $I)
+	{
+		// Create a page with a Legacy Form assignment.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Gutenberg: Form',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'         => (string) $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+						'landing_page' => '',
+						'tag'          => '',
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->waitForElementVisible($this->noticeSelector);
+
+		// Assert the notice displays the legacy form by name.
+		$I->see('Form: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+
+		// Assert the notice does not have a dismiss button.
+		$I->dontSeeElementInDOM($this->noticeSelector . ' button.components-notice__dismiss');
+	}
+
+	/**
+	 * Test that a page with a legacy Landing Page assignment displays the
+	 * warning notice inside Gutenberg, listing the legacy landing page by
+	 * name.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDisplaysForLegacyLandingPage(EndToEndTester $I)
+	{
+		// Create a page with a Legacy Landing Page assignment.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Gutenberg: Landing Page',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'         => '0',
+						'landing_page' => (string) $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_ID'],
+						'tag'          => '',
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->waitForElementVisible($this->noticeSelector);
+
+		// Assert the notice displays the legacy landing page by name.
+		$I->see('Landing Page: ' . $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_NAME'], $this->noticeSelector);
+
+		// Assert the notice does not have a dismiss button.
+		$I->dontSeeElementInDOM($this->noticeSelector . ' button.components-notice__dismiss');
+	}
+
+	/**
+	 * Test that a page with a Restrict Content assignment referencing a
+	 * legacy Kit form displays the warning notice inside Gutenberg, scoped
+	 * to Member Content.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDisplaysForLegacyRestrictContentForm(EndToEndTester $I)
+	{
+		// Create a page with a Restrict Content assignment referencing a
+		// legacy Kit form.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Gutenberg: Restrict Content',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'             => '0',
+						'landing_page'     => '',
+						'tag'              => '',
+						'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->waitForElementVisible($this->noticeSelector);
+
+		// Assert the notice displays the legacy form by name.
+		$I->see('Member Content: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+
+		// Assert the notice does not have a dismiss button.
+		$I->dontSeeElementInDOM($this->noticeSelector . ' button.components-notice__dismiss');
+	}
+
+	/**
+	 * Test that a page assigning only v4 Kit resources does not display
+	 * the legacy warning notice inside Gutenberg.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDoesNotDisplayForV4Resources(EndToEndTester $I)
+	{
+		// Create a page assigning only v4 Kit resources.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Gutenberg: V4 Only',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'         => (string) $_ENV['CONVERTKIT_API_FORM_ID'],
+						'landing_page' => (string) $_ENV['CONVERTKIT_API_LANDING_PAGE_ID'],
+						'tag'          => '',
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for Gutenberg to settle.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+
+		// Assert the notice is not present.
+		$I->waitForElementVisible('.block-editor');
+		$I->dontSeeElementInDOM($this->noticeSelector);
+	}
+
+	/**
+	 * Test that a page with legacy form + legacy landing page + legacy
+	 * Member Content assignments displays a single consolidated warning
+	 * notice inside Gutenberg with all three items listed.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testConsolidatedNoticeWhenMultipleLegacy(EndToEndTester $I)
+	{
+		// Create a page with legacy form + legacy landing page + legacy
+		// Member Content assignments.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Gutenberg: Consolidated',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'             => (string) $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+						'landing_page'     => (string) $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_ID'],
+						'tag'              => '',
+						'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->waitForElementVisible($this->noticeSelector);
+
+		// Assert the notice displays all three legacy resources.
+		$I->seeNumberOfElementsInDOM($this->noticeSelector, 1);
+		$I->see('Form: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+		$I->see('Landing Page: ' . $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_NAME'], $this->noticeSelector);
+		$I->see('Member Content: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+	}
+
+	/**
+	 * Deactivate and reset Plugin(s) after each test, if the test passes.
+	 * We don't use _after, as this would provide a screenshot of the Plugin
+	 * deactivation and not the true test error.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function _passed(EndToEndTester $I)
+	{
+		$I->deactivateKitPlugin($I);
+		$I->resetKitPlugin($I);
+	}
+}
diff --git a/tests/EndToEnd/general/other/ClassicEditorLegacyNoticeCest.php b/tests/EndToEnd/general/other/ClassicEditorLegacyNoticeCest.php
new file mode 100644
index 000000000..91040f2bf
--- /dev/null
+++ b/tests/EndToEnd/general/other/ClassicEditorLegacyNoticeCest.php
@@ -0,0 +1,239 @@
+<?php
+
+namespace Tests\EndToEnd;
+
+use Tests\Support\EndToEndTester;
+
+/**
+ * Tests the non-dismissible legacy-resource warning notice output by
+ * ConvertKit_Admin_Legacy_Resource_Notice on the Classic editor's post
+ * edit screen.
+ *
+ * @since   3.3.7
+ */
+class ClassicEditorLegacyNoticeCest
+{
+	/**
+	 * The CSS selector matching the warning notice on the classic editor.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @var     string
+	 */
+	private $noticeSelector = 'div.notice.notice-warning';
+
+	/**
+	 * Run common actions before running the test functions in this class.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function _before(EndToEndTester $I)
+	{
+		$I->activateKitPlugin($I);
+		$I->activateThirdPartyPlugin($I, 'classic-editor');
+		$I->setupKitPlugin($I);
+		$I->setupKitPluginResources($I);
+	}
+
+	/**
+	 * Test that a page with a legacy Form assignment displays the warning
+	 * notice on the classic editor, listing the legacy form by name.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDisplaysForLegacyForm(EndToEndTester $I)
+	{
+		// Create a page with a Legacy Form assignment.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Form',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'         => (string) $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+						'landing_page' => '',
+						'tag'          => '',
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->seeElementInDOM($this->noticeSelector);
+
+		// Assert the notice displays the legacy form by name.
+		$I->see('Form: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+
+		// Assert the notice does not have a dismiss button.
+		$I->dontSeeElementInDOM($this->noticeSelector . ' button.notice-dismiss');
+	}
+
+	/**
+	 * Test that a page with a legacy Landing Page assignment displays the
+	 * warning notice on the classic editor, listing the legacy landing
+	 * page by name.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDisplaysForLegacyLandingPage(EndToEndTester $I)
+	{
+		// Create a page with a Legacy Landing Page assignment.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Landing Page',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'         => '0',
+						'landing_page' => (string) $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_ID'],
+						'tag'          => '',
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->seeElementInDOM($this->noticeSelector);
+
+		// Assert the notice displays the legacy landing page by name.
+		$I->see('Landing Page: ' . $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_NAME'], $this->noticeSelector);
+
+		// Assert the notice does not have a dismiss button.
+		$I->dontSeeElementInDOM($this->noticeSelector . ' button.notice-dismiss');
+	}
+
+	/**
+	 * Test that a page with a Restrict Content assignment referencing a
+	 * legacy Kit form displays the warning notice on the classic editor,
+	 * scoped to Member Content.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDisplaysForLegacyRestrictContentForm(EndToEndTester $I)
+	{
+		// Create a page with a Restrict Content assignment referencing a
+		// legacy Kit form.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Restrict Content',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'             => '0',
+						'landing_page'     => '',
+						'tag'              => '',
+						'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+		$I->seeElementInDOM($this->noticeSelector);
+
+		// Assert the notice displays the legacy form by name.
+		$I->see('Member Content: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+
+		// Assert the notice does not have a dismiss button.
+		$I->dontSeeElementInDOM($this->noticeSelector . ' button.notice-dismiss');
+	}
+
+	/**
+	 * Test that a page assigning only v4 Kit resources does not display
+	 * the legacy warning notice.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testNoticeDoesNotDisplayForV4Resources(EndToEndTester $I)
+	{
+		// Create a page assigning only v4 Kit resources.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: V4 Only',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'         => (string) $_ENV['CONVERTKIT_API_FORM_ID'],
+						'landing_page' => (string) $_ENV['CONVERTKIT_API_LANDING_PAGE_ID'],
+						'tag'          => '',
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+
+		// Assert the notice is not present.
+		$I->dontSee('Kit: This page uses one or more legacy Kit resources');
+	}
+
+	/**
+	 * Test that a page with legacy form + legacy landing page + legacy
+	 * Member Content assignments displays a single consolidated warning
+	 * notice with all three items listed.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function testConsolidatedNoticeWhenMultipleLegacyResources(EndToEndTester $I)
+	{
+		// Create a page with legacy form + legacy landing page + legacy
+		// Member Content assignments.
+		$pageID = $I->havePageInDatabase(
+			[
+				'post_status' => 'publish',
+				'post_title'  => 'Kit: Legacy Notice: Consolidated',
+				'meta_input'  => [
+					'_wp_convertkit_post_meta' => [
+						'form'             => (string) $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+						'landing_page'     => (string) $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_ID'],
+						'tag'              => '',
+						'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+					],
+				],
+			]
+		);
+
+		// Navigate to the page and wait for the notice to appear.
+		$I->amOnAdminPage('post.php?post=' . $pageID . '&action=edit');
+
+		// Assert the notice displays all three legacy resources.
+		$I->seeNumberOfElementsInDOM($this->noticeSelector, 1);
+		$I->see('Form: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+
+		// Assert the notice displays the legacy landing page by name.
+		$I->see('Landing Page: ' . $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_NAME'], $this->noticeSelector);
+		$I->see('Member Content: ' . $_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $this->noticeSelector);
+	}
+
+	/**
+	 * Deactivate and reset Plugin(s) after each test, if the test passes.
+	 * We don't use _after, as this would provide a screenshot of the Plugin
+	 * deactivation and not the true test error.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @param   EndToEndTester $I  Tester.
+	 */
+	public function _passed(EndToEndTester $I)
+	{
+		$I->deactivateThirdPartyPlugin($I, 'classic-editor');
+		$I->deactivateKitPlugin($I);
+		$I->resetKitPlugin($I);
+	}
+}
diff --git a/tests/Integration/AdminLegacyResourceNoticeTest.php b/tests/Integration/AdminLegacyResourceNoticeTest.php
new file mode 100644
index 000000000..26ac6bbe8
--- /dev/null
+++ b/tests/Integration/AdminLegacyResourceNoticeTest.php
@@ -0,0 +1,228 @@
+<?php
+
+namespace Tests;
+
+use lucatume\WPBrowser\TestCase\WPTestCase;
+
+/**
+ * Tests for the ConvertKit_Admin_Legacy_Resource_Notice class.
+ *
+ * @since   3.3.7
+ */
+class AdminLegacyResourceNoticeTest extends WPTestCase
+{
+	/**
+	 * The testing implementation.
+	 *
+	 * @var \IntegrationTester
+	 */
+	protected $tester;
+
+	/**
+	 * Holds the notice class.
+	 *
+	 * @since   3.3.7
+	 *
+	 * @var     \ConvertKit_Admin_Legacy_Resource_Notice
+	 */
+	private $notice;
+
+	/**
+	 * Performs actions before each test.
+	 *
+	 * @since   3.3.7
+	 */
+	public function setUp(): void
+	{
+		parent::setUp();
+
+		activate_plugins('convertkit/wp-convertkit.php');
+
+		// Store credentials in Plugin's settings.
+		$settings = new \ConvertKit_Settings();
+		update_option(
+			$settings::SETTINGS_NAME,
+			[
+				'access_token'  => $_ENV['CONVERTKIT_OAUTH_ACCESS_TOKEN'],
+				'refresh_token' => $_ENV['CONVERTKIT_OAUTH_REFRESH_TOKEN'],
+			]
+		);
+
+		// Refresh Forms and Landing Pages resources so is_legacy() calls resolve
+		// correctly against the API-backed cache.
+		$forms = new \ConvertKit_Resource_Forms();
+		$forms->refresh();
+
+		$landing_pages = new \ConvertKit_Resource_Landing_Pages();
+		$landing_pages->refresh();
+
+		$this->notice = new \ConvertKit_Admin_Legacy_Resource_Notice();
+	}
+
+	/**
+	 * Test that a settings array with only v4 resource assignments returns
+	 * no warnings.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testNoWarningsForV4Resources()
+	{
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'form'             => $_ENV['CONVERTKIT_API_FORM_ID'],
+				'landing_page'     => $_ENV['CONVERTKIT_API_LANDING_PAGE_ID'],
+				'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_FORM_ID'],
+			]
+		);
+
+		$this->assertSame([], $warnings);
+	}
+
+	/**
+	 * Test that a legacy form assignment produces a form-scoped warning
+	 * containing the form's name.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testWarningForLegacyForm()
+	{
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'form' => $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+			]
+		);
+
+		$this->assertCount(1, $warnings);
+		$this->assertStringContainsString('Form:', $warnings[0]);
+		$this->assertStringContainsString($_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $warnings[0]);
+	}
+
+	/**
+	 * Test that a legacy landing page assignment (by numeric ID) produces
+	 * a landing-page-scoped warning containing the landing page's name.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testWarningForLegacyLandingPageByID()
+	{
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'landing_page' => $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_ID'],
+			]
+		);
+
+		$this->assertCount(1, $warnings);
+		$this->assertStringContainsString('Landing Page:', $warnings[0]);
+		$this->assertStringContainsString($_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_NAME'], $warnings[0]);
+	}
+
+	/**
+	 * Test that a legacy landing page assignment stored as a URL string
+	 * (pre-1.9.6 storage) produces a landing-page-scoped warning using the
+	 * fallback label since we can't resolve a name from the URL alone.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testWarningForLegacyLandingPageByURL()
+	{
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'landing_page' => $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_URL'],
+			]
+		);
+
+		$this->assertCount(1, $warnings);
+		$this->assertStringContainsString('Landing Page:', $warnings[0]);
+		$this->assertStringContainsString('a Legacy Landing Page', $warnings[0]);
+	}
+
+	/**
+	 * Test that a restrict_content value of `form_<legacy_id>` produces a
+	 * Member Content warning.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testWarningForLegacyRestrictContentForm()
+	{
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+			]
+		);
+
+		$this->assertCount(1, $warnings);
+		$this->assertStringContainsString('Member Content:', $warnings[0]);
+		$this->assertStringContainsString($_ENV['CONVERTKIT_API_LEGACY_FORM_NAME'], $warnings[0]);
+	}
+
+	/**
+	 * Test that restrict_content values of `tag_<id>` and `product_<id>`
+	 * never trigger a warning, because tags and products have no legacy
+	 * variant.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testNoWarningForLegacyRestrictContentTagOrProduct()
+	{
+		$tag     = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'restrict_content' => 'tag_' . $_ENV['CONVERTKIT_API_TAG_ID'],
+			]
+		);
+		$product = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'restrict_content' => 'product_1',
+			]
+		);
+
+		$this->assertSame([], $tag);
+		$this->assertSame([], $product);
+	}
+
+	/**
+	 * Test that a settings array with legacy form + legacy landing page +
+	 * legacy restrict_content form produces three warnings in a single
+	 * returned array.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testWarningsForMultipleLegacyResources()
+	{
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'form'             => $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+				'landing_page'     => $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_ID'],
+				'restrict_content' => 'form_' . $_ENV['CONVERTKIT_API_LEGACY_FORM_ID'],
+			]
+		);
+
+		$this->assertCount(3, $warnings);
+	}
+
+	/**
+	 * Test that when a legacy form ID doesn't resolve to any cached resource
+	 * (e.g. the form was deleted from the Kit account), the warning falls
+	 * back to "a Legacy Form" rather than omitting the entry.
+	 *
+	 * @since   3.3.7
+	 */
+	public function testWarningWithMissingResourceFallsBackToLabel()
+	{
+		// Wipe the Forms cache so is_legacy() can no longer resolve any
+		// numeric ID to a real resource. is_legacy() will therefore return
+		// false for numeric IDs — but a URL-based landing page assignment
+		// still resolves as legacy by the URL-string check, exercising the
+		// name-fallback path.
+		delete_option('convertkit_forms');
+		delete_option('convertkit_landing_pages');
+
+		$warnings = $this->notice->get_legacy_warnings_for_post_settings(
+			[
+				'landing_page' => $_ENV['CONVERTKIT_API_LEGACY_LANDING_PAGE_URL'],
+			]
+		);
+
+		$this->assertCount(1, $warnings);
+		$this->assertStringContainsString('a Legacy Landing Page', $warnings[0]);
+	}
+}
diff --git a/wp-convertkit.php b/wp-convertkit.php
index caead13e1..a400ce5fd 100644
--- a/wp-convertkit.php
+++ b/wp-convertkit.php
@@ -111,6 +111,7 @@
 require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-cache-plugins.php';
 require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-category.php';
 require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-landing-page.php';
+require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-legacy-resource-notice.php';
 require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-post.php';
 require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-refresh-resources.php';
 require_once CONVERTKIT_PLUGIN_PATH . '/admin/class-convertkit-admin-restrict-content.php';