diff --git a/autoload.php b/autoload.php
index 68e2e8f9d4b..b31362efab9 100644
--- a/autoload.php
+++ b/autoload.php
@@ -967,6 +967,7 @@ $wgAutoloadLocalClasses = [
 	'MediaWiki\\Hook\\ParserLimitReportFormatHook' => __DIR__ . '/includes/parser/Hook/ParserLimitReportFormatHook.php',
 	'MediaWiki\\Hook\\ParserLimitReportPrepareHook' => __DIR__ . '/includes/parser/Hook/ParserLimitReportPrepareHook.php',
 	'MediaWiki\\Hook\\ParserMakeImageParamsHook' => __DIR__ . '/includes/parser/Hook/ParserMakeImageParamsHook.php',
+	'MediaWiki\\Hook\\ParserModifyImageHTML' => __DIR__ . '/includes/parser/Hook/ParserModifyImageHTML.php',
 	'MediaWiki\\Hook\\ParserOptionsRegisterHook' => __DIR__ . '/includes/parser/Hook/ParserOptionsRegisterHook.php',
 	'MediaWiki\\Hook\\ParserOutputPostCacheTransformHook' => __DIR__ . '/includes/parser/Hook/ParserOutputPostCacheTransformHook.php',
 	'MediaWiki\\Hook\\ParserPreSaveTransformCompleteHook' => __DIR__ . '/includes/parser/Hook/ParserPreSaveTransformCompleteHook.php',
diff --git a/includes/HookContainer/HookRunner.php b/includes/HookContainer/HookRunner.php
index fc4646e790b..3dcc0eb5422 100644
--- a/includes/HookContainer/HookRunner.php
+++ b/includes/HookContainer/HookRunner.php
@@ -4,6 +4,7 @@ namespace MediaWiki\HookContainer;
 
 use Article;
 use Config;
+use File;
 use IContextSource;
 use ManualLogEntry;
 use MediaWiki\Linker\LinkRenderer;
@@ -12,6 +13,7 @@ use MediaWiki\Page\ProperPageIdentity;
 use MediaWiki\Permissions\Authority;
 use MediaWiki\Revision\RevisionRecord;
 use MediaWiki\User\UserIdentity;
+use Parser;
 use ParserOptions;
 use ResourceLoaderContext;
 use Skin;
@@ -287,6 +289,7 @@ class HookRunner implements
 	\MediaWiki\Hook\ParserLimitReportFormatHook,
 	\MediaWiki\Hook\ParserLimitReportPrepareHook,
 	\MediaWiki\Hook\ParserMakeImageParamsHook,
+	\MediaWiki\Hook\ParserModifyImageHTML,
 	\MediaWiki\Hook\ParserOptionsRegisterHook,
 	\MediaWiki\Hook\ParserOutputPostCacheTransformHook,
 	\MediaWiki\Hook\ParserPreSaveTransformCompleteHook,
@@ -2915,6 +2918,16 @@ class HookRunner implements
 		);
 	}
 
+	public function onParserModifyImageHTML( Parser $parser, File $file,
+		array $params, string &$html
+	): void {
+		$this->container->run(
+			'ParserModifyImageHTML',
+			[ $parser, $file, $params, &$html ],
+			[ 'abortable' => false ]
+		);
+	}
+
 	public function onParserOptionsRegister( &$defaults, &$inCacheKey, &$lazyLoad ) {
 		return $this->container->run(
 			'ParserOptionsRegister',
diff --git a/includes/gallery/TraditionalImageGallery.php b/includes/gallery/TraditionalImageGallery.php
index 3340963b3e7..b5e155a1efa 100644
--- a/includes/gallery/TraditionalImageGallery.php
+++ b/includes/gallery/TraditionalImageGallery.php
@@ -197,10 +197,16 @@ class TraditionalImageGallery extends ImageGalleryBase {
 					], $thumbhtml );
 
 					// Call parser transform hook
-					/** @var MediaHandler $handler */
-					$handler = $img->getHandler();
-					if ( $resolveFilesViaParser && $handler ) {
-						$handler->parserTransformHook( $this->mParser, $img );
+					if ( $resolveFilesViaParser ) {
+						/** @var MediaHandler $handler */
+						$handler = $img->getHandler();
+						if ( $handler ) {
+							$handler->parserTransformHook( $this->mParser, $img );
+						}
+						if ( $img ) {
+							$this->mParser->modifyImageHtml(
+								$img, [ 'handler' => $imageParameters ], $thumbhtml );
+						}
 					}
 				}
 			}
diff --git a/includes/parser/Hook/ParserModifyImageHTML.php b/includes/parser/Hook/ParserModifyImageHTML.php
new file mode 100644
index 00000000000..f51d3d6b52e
--- /dev/null
+++ b/includes/parser/Hook/ParserModifyImageHTML.php
@@ -0,0 +1,30 @@
+<?php
+
+namespace MediaWiki\Hook;
+
+use File;
+use Parser;
+
+/**
+ * This is a hook handler interface, see docs/Hooks.md.
+ * Use the hook name "ParserModifyImageHTML" to register handlers implementing this interface.
+ *
+ * @stable to implement
+ * @ingroup Hooks
+ */
+interface ParserModifyImageHTML {
+	/**
+	 * This hook is called for each image added to parser output, with its
+	 * associated HTML as returned from Linker::makeImageLink().
+	 *
+	 * @param Parser $parser
+	 * @param File $file
+	 * @param array $params An associative array of options that were used to generate the HTML.
+	 *   Like the one sent to onParserMakeImageParams.  The 'handler' element contains handler
+	 *   options. The 'frame' element contains frame options. In the image gallery case, "frame"
+	 *   will be missing.
+	 * @param string &$html The HTML of the image or image wrapper
+	 */
+	public function onParserModifyImageHTML( Parser $parser, File $file,
+		array $params, string &$html ): void;
+}
diff --git a/includes/parser/Parser.php b/includes/parser/Parser.php
index 23319c7b75b..ea3bda6dc15 100644
--- a/includes/parser/Parser.php
+++ b/includes/parser/Parser.php
@@ -5453,6 +5453,9 @@ class Parser {
 		if ( $handler ) {
 			$handler->parserTransformHook( $this, $file );
 		}
+		if ( $file ) {
+			$this->modifyImageHtml( $file, $params, $ret );
+		}
 
 		return $ret;
 	}
@@ -5500,6 +5503,17 @@ class Parser {
 		return [ $type, $target ];
 	}
 
+	/**
+	 * Give hooks a chance to modify image thumbnail HTML
+	 *
+	 * @param File $file
+	 * @param array $params
+	 * @param string &$html
+	 */
+	public function modifyImageHtml( File $file, array $params, string &$html ) {
+		$this->hookRunner->onParserModifyImageHTML( $this, $file, $params, $html );
+	}
+
 	/**
 	 * @param string $caption
 	 * @param LinkHolderArray|bool $holders