diff --git a/lib/routes/mastodon/tag.ts b/lib/routes/mastodon/tag.ts
new file mode 100644
index 0000000000..35d5a92aa1
--- /dev/null
+++ b/lib/routes/mastodon/tag.ts
@@ -0,0 +1,48 @@
+import { Route, ViewType, Data } from '@/types';
+
+import got from '@/utils/got';
+import { Context } from 'hono';
+import utils from './utils';
+import { config } from '@/config';
+import ConfigNotFoundError from '@/errors/types/config-not-found';
+
+export const route: Route = {
+    path: '/tag/:site/:hashtag/:only_media?',
+    categories: ['social-media'],
+    view: ViewType.SocialMedia,
+    example: '/mastodon/tag/mastodon.social/gochisou/true',
+    parameters: {
+        site: 'instance address, only domain, no `http://` or `https://` protocol header',
+        hashtag: 'Hashtag you want to subscribe to (without the # symbol)',
+        only_media: {
+            description: 'whether only display media content, default to false, any value to true',
+            options: [
+                { value: 'true', label: 'true' },
+                { value: 'false', label: 'false' },
+            ],
+            default: 'false',
+        },
+    },
+    name: 'Hashtag timeline',
+    maintainers: ['yuikisaito'],
+    handler,
+};
+
+async function handler(ctx: Context): Promise<Data> {
+    const { site, hashtag } = ctx.req.param();
+    const only_media = ctx.req.param('only_media') === 'true' ? 'true' : 'false';
+    if (!config.feature.allow_user_supply_unsafe_domain && !utils.allowSiteList.includes(site)) {
+        throw new ConfigNotFoundError(`This RSS is disabled unless 'ALLOW_USER_SUPPLY_UNSAFE_DOMAIN' is set to 'true'.`);
+    }
+
+    const url = `http://${site}/api/v1/timelines/tag/${hashtag}?only_media=${only_media}`;
+
+    const response = await got.get(url, { headers: utils.apiHeaders(site) });
+    const list = response.data;
+
+    return {
+        title: `#${hashtag} ${only_media === 'true' ? ' Media' : ''} Timeline on ${site}`,
+        link: `https://${site}`,
+        item: utils.parseStatuses(list),
+    };
+}