diff --git a/src/js/_enqueues/vendor/plupload/handlers.js b/src/js/_enqueues/vendor/plupload/handlers.js
index 1edfc5cf42..884d8596fc 100644
--- a/src/js/_enqueues/vendor/plupload/handlers.js
+++ b/src/js/_enqueues/vendor/plupload/handlers.js
@@ -568,6 +568,11 @@ jQuery( document ).ready( function( $ ) {
 			uploadStart();
 
 			plupload.each( files, function( file ) {
+				if ( file.type === 'image/heic' && up.settings.heic_upload_error ) {
+					// Show error but do not block uploading.
+					wpQueueError( pluploadL10n.unsupported_image )
+				}
+
 				fileQueued( file );
 			});
 
diff --git a/src/js/_enqueues/vendor/plupload/wp-plupload.js b/src/js/_enqueues/vendor/plupload/wp-plupload.js
index c89553b2de..7ac790ec00 100644
--- a/src/js/_enqueues/vendor/plupload/wp-plupload.js
+++ b/src/js/_enqueues/vendor/plupload/wp-plupload.js
@@ -351,6 +351,15 @@ window.wp = window.wp || {};
 					return;
 				}
 
+				if ( file.type === 'image/heic' && up.settings.heic_upload_error ) {
+					// Show error but do not block uploading.
+					Uploader.errors.unshift({
+						message: pluploadL10n.unsupported_image,
+						data:    {},
+						file:    file
+					});
+				}
+
 				// Generate attributes for a new `Attachment` model.
 				attributes = _.extend({
 					file:      file,
diff --git a/src/wp-admin/includes/admin-filters.php b/src/wp-admin/includes/admin-filters.php
index 7f9e09e0ed..345a6114af 100644
--- a/src/wp-admin/includes/admin-filters.php
+++ b/src/wp-admin/includes/admin-filters.php
@@ -15,6 +15,7 @@ add_action( 'activity_box_end', 'wp_dashboard_quota' );
 
 // Media hooks.
 add_action( 'attachment_submitbox_misc_actions', 'attachment_submitbox_metadata' );
+add_filter( 'plupload_init', 'wp_show_heic_upload_error' );
 
 add_action( 'media_upload_image', 'wp_media_upload_handler' );
 add_action( 'media_upload_audio', 'wp_media_upload_handler' );
diff --git a/src/wp-includes/default-filters.php b/src/wp-includes/default-filters.php
index 2fd1d33b69..dc51908604 100644
--- a/src/wp-includes/default-filters.php
+++ b/src/wp-includes/default-filters.php
@@ -534,6 +534,7 @@ add_filter( 'the_content', 'do_shortcode', 11 ); // AFTER wpautop().
 add_action( 'wp_playlist_scripts', 'wp_playlist_scripts' );
 add_action( 'customize_controls_enqueue_scripts', 'wp_plupload_default_settings' );
 add_action( 'plugins_loaded', '_wp_add_additional_image_sizes', 0 );
+add_filter( 'plupload_default_settings', 'wp_show_heic_upload_error' );
 
 // Nav menu.
 add_filter( 'nav_menu_item_id', '_nav_menu_item_id_use_once', 10, 2 );
diff --git a/src/wp-includes/functions.php b/src/wp-includes/functions.php
index 4fea38c7fa..5a2abd808c 100644
--- a/src/wp-includes/functions.php
+++ b/src/wp-includes/functions.php
@@ -3046,6 +3046,7 @@ function wp_get_mime_types() {
 			'bmp'                          => 'image/bmp',
 			'tiff|tif'                     => 'image/tiff',
 			'ico'                          => 'image/x-icon',
+			'heic'                         => 'image/heic',
 			// Video formats.
 			'asf|asx'                      => 'video/x-ms-asf',
 			'wmv'                          => 'video/x-ms-wmv',
diff --git a/src/wp-includes/media.php b/src/wp-includes/media.php
index 5fe27ba113..18cc3d6d30 100644
--- a/src/wp-includes/media.php
+++ b/src/wp-includes/media.php
@@ -3599,8 +3599,10 @@ function wp_plupload_default_settings() {
 	 *
 	 * @param array $params Default Plupload parameters array.
 	 */
-	$params                       = apply_filters( 'plupload_default_params', $params );
-	$params['_wpnonce']           = wp_create_nonce( 'media-form' );
+	$params = apply_filters( 'plupload_default_params', $params );
+
+	$params['_wpnonce'] = wp_create_nonce( 'media-form' );
+
 	$defaults['multipart_params'] = $params;
 
 	$settings = array(
@@ -4686,3 +4688,16 @@ function _wp_add_additional_image_sizes() {
 	// 2x large size.
 	add_image_size( '2048x2048', 2048, 2048 );
 }
+
+/**
+ * Callback to enable showig of the user error when uploading .heic images.
+ *
+ * @since 5.5.0
+ *
+ * @param array[] $plupload_settings The settings for Plupload.js.
+ * @return array[] Modified settings for Plupload.js.
+ */
+function wp_show_heic_upload_error( $plupload_settings ) {
+	$plupload_settings['heic_upload_error'] = true;
+	return $plupload_settings;
+}
diff --git a/src/wp-includes/script-loader.php b/src/wp-includes/script-loader.php
index 63e5d08a7f..30a4090b37 100644
--- a/src/wp-includes/script-loader.php
+++ b/src/wp-includes/script-loader.php
@@ -846,6 +846,7 @@ function wp_default_scripts( $scripts ) {
 		'deleted'                   => __( 'moved to the Trash.' ),
 		/* translators: %s: File name. */
 		'error_uploading'           => __( '“%s” has failed to upload.' ),
+		'unsupported_image'         => __( 'This image cannot be displayed in a web browser. For best results convert it to JPEG before uploading.' ),
 	);
 
 	$scripts->add( 'moxiejs', "/wp-includes/js/plupload/moxie$suffix.js", array(), '1.3.5' );