diff --git a/src/Module/Api/Mastodon/Accounts/Lookup.php b/src/Module/Api/Mastodon/Accounts/Lookup.php
new file mode 100644
index 0000000000..d7a080fb8e
--- /dev/null
+++ b/src/Module/Api/Mastodon/Accounts/Lookup.php
@@ -0,0 +1,56 @@
+<?php
+/**
+ * @copyright Copyright (C) 2010-2024, the Friendica project
+ *
+ * @license GNU AGPL version 3 or any later version
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+namespace Friendica\Module\Api\Mastodon\Accounts;
+
+use Friendica\Core\Protocol;
+use Friendica\DI;
+use Friendica\Model\Contact;
+use Friendica\Module\BaseApi;
+
+/**
+ * @see https://docs.joinmastodon.org/methods/accounts/#lookup
+ */
+class Lookup extends BaseApi
+{
+	/**
+	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
+	 */
+	protected function rawContent(array $request = [])
+	{
+		$this->checkAllowedScope(self::SCOPE_READ);
+		$uid = self::getCurrentUserID();
+
+		$request = $this->getRequest([
+			'acct' => '', // The username or Webfinger address to lookup.
+		], $request);
+
+		if (empty($request['acct'])) {
+			$this->logAndJsonError(404, $this->errorFactory->RecordNotFound());
+		}
+		$contact = Contact::getByURL($request['acct'], null, ['id', 'network', 'failed', 'blocked']);
+		if (empty($contact) || ($contact['network'] == Protocol::PHANTOM) || $contact['failed'] || $contact['blocked']) {
+			$this->logAndJsonError(404, $this->errorFactory->RecordNotFound());
+		}
+
+		$this->jsonExit(DI::mstdnAccount()->createFromContactId($contact['id'], $uid));
+	}
+}
diff --git a/static/routes.config.php b/static/routes.config.php
index c52c04d954..affbf5a42a 100644
--- a/static/routes.config.php
+++ b/static/routes.config.php
@@ -211,7 +211,7 @@ return [
 			'/accounts/{id:\d+}/note'            => [Module\Api\Mastodon\Accounts\Note::class,            [        R::POST]],
 			'/accounts/{id:\d+}/remove_from_followers' => [Module\Api\Mastodon\Unimplemented::class,      [        R::POST]], // not supported
 			'/accounts/familiar_followers'       => [Module\Api\Mastodon\Unimplemented::class,            [R::GET         ]], // not supported
-			'/accounts/lookup'                   => [Module\Api\Mastodon\Unimplemented::class,            [R::GET         ]], // not supported
+			'/accounts/lookup'                   => [Module\Api\Mastodon\Accounts\Lookup::class,          [R::GET         ]],
 			'/accounts/relationships'            => [Module\Api\Mastodon\Accounts\Relationships::class,   [R::GET         ]],
 			'/accounts/search'                   => [Module\Api\Mastodon\Accounts\Search::class,          [R::GET         ]],
 			'/accounts/update_credentials'       => [Module\Api\Mastodon\Accounts\UpdateCredentials::class, [R::PATCH     ]],