diff --git a/src/api/endpoints/posts/search.ts b/src/api/endpoints/posts/search.ts
index 6e26f55390..a36d1178a5 100644
--- a/src/api/endpoints/posts/search.ts
+++ b/src/api/endpoints/posts/search.ts
@@ -121,6 +121,15 @@ async function search(
 				text: x
 			});
 		} else {
+			const tags = text.split(' ').filter(x => x[0] == '#');
+			if (tags) {
+				push({
+					$and: tags.map(x => ({
+						tags: x
+					}))
+				});
+			}
+
 			push({
 				$and: text.split(' ').map(x => ({
 					// キーワードが-で始まる場合そのキーワードを除外する
diff --git a/src/web/app/desktop/views/components/post-detail.vue b/src/web/app/desktop/views/components/post-detail.vue
index 1e31752fe7..e6e0ffa021 100644
--- a/src/web/app/desktop/views/components/post-detail.vue
+++ b/src/web/app/desktop/views/components/post-detail.vue
@@ -45,7 +45,7 @@
 			</div>
 			<mk-poll v-if="p.poll" :post="p"/>
 			<div class="tags" v-if="p.tags && p.tags.length > 0">
-				<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=${tag}`">{{ tag }}</router-link>
+				<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=#${tag}`">{{ tag }}</router-link>
 			</div>
 		</div>
 		<footer>
diff --git a/src/web/app/desktop/views/components/posts.post.vue b/src/web/app/desktop/views/components/posts.post.vue
index 382a8de97d..647590e25d 100644
--- a/src/web/app/desktop/views/components/posts.post.vue
+++ b/src/web/app/desktop/views/components/posts.post.vue
@@ -39,7 +39,7 @@
 					<a class="reply" v-if="p.reply">%fa:reply%</a>
 					<mk-post-html v-if="p.ast" :ast="p.ast" :i="os.i" :class="$style.text"/>
 					<div class="tags" v-if="p.tags && p.tags.length > 0">
-						<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=${tag}`">{{ tag }}</router-link>
+						<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=#${tag}`">{{ tag }}</router-link>
 					</div>
 					<a class="quote" v-if="p.repost">RP:</a>
 					<mk-url-preview v-for="url in urls" :url="url" :key="url"/>
diff --git a/src/web/app/mobile/views/components/post-detail.vue b/src/web/app/mobile/views/components/post-detail.vue
index a83744ec4d..ae1c3fdc99 100644
--- a/src/web/app/mobile/views/components/post-detail.vue
+++ b/src/web/app/mobile/views/components/post-detail.vue
@@ -40,7 +40,7 @@
 		<div class="body">
 			<mk-post-html v-if="p.ast" :ast="p.ast" :i="os.i" :class="$style.text"/>
 			<div class="tags" v-if="p.tags && p.tags.length > 0">
-				<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=${tag}`">{{ tag }}</router-link>
+				<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=#${tag}`">{{ tag }}</router-link>
 			</div>
 			<mk-url-preview v-for="url in urls" :url="url" :key="url"/>
 			<div class="media" v-if="p.media">
diff --git a/src/web/app/mobile/views/components/posts.post.vue b/src/web/app/mobile/views/components/posts.post.vue
index e26c337f5c..b94d9d16bd 100644
--- a/src/web/app/mobile/views/components/posts.post.vue
+++ b/src/web/app/mobile/views/components/posts.post.vue
@@ -36,7 +36,7 @@
 					</a>
 					<mk-post-html v-if="p.ast" :ast="p.ast" :i="os.i" :class="$style.text"/>
 					<div class="tags" v-if="p.tags && p.tags.length > 0">
-						<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=${tag}`">{{ tag }}</router-link>
+						<router-link v-for="tag in p.tags" :key="tag" :to="`/search?q=#${tag}`">{{ tag }}</router-link>
 					</div>
 					<mk-url-preview v-for="url in urls" :url="url" :key="url"/>
 					<a class="quote" v-if="p.repost != null">RP:</a>
diff --git a/src/web/docs/search.ja.pug b/src/web/docs/search.ja.pug
index f33091ee6b..e14e8c867e 100644
--- a/src/web/docs/search.ja.pug
+++ b/src/web/docs/search.ja.pug
@@ -16,6 +16,10 @@ section
 	p テキストを「"""」で囲むと、そのテキストと完全に一致する投稿を検索します。
 	p 例えば、「"""にゃーん"""」と検索すると、「にゃーん」という投稿のみがヒットし、「にゃーん…」という投稿はヒットしません。
 
+section
+	h2 タグ
+	p キーワードの前に「#」(シャープ)をプリフィクスすると、そのキーワードと一致するタグを持つ投稿に限定します。
+
 section
 	h2 オプション
 	p