diff --git a/locales/index.d.ts b/locales/index.d.ts
index 2c64a6d373..177c9685a1 100644
--- a/locales/index.d.ts
+++ b/locales/index.d.ts
@@ -5662,6 +5662,10 @@ export interface Locale extends ILocale {
          * オフのとき
          */
         "ifOff": string;
+        /**
+         * デバイス間でインストールしたテーマを同期
+         */
+        "enableSyncThemesBetweenDevices": string;
         "_chat": {
             /**
              * 送信者の名前を表示
diff --git a/locales/ja-JP.yml b/locales/ja-JP.yml
index 322506965c..483ece655d 100644
--- a/locales/ja-JP.yml
+++ b/locales/ja-JP.yml
@@ -1416,6 +1416,7 @@ _settings:
   showNavbarSubButtons: "ナビゲーションバーに副ボタンを表示"
   ifOn: "オンのとき"
   ifOff: "オフのとき"
+  enableSyncThemesBetweenDevices: "デバイス間でインストールしたテーマを同期"
 
   _chat:
     showSenderName: "送信者の名前を表示"
diff --git a/packages/frontend/src/pages/settings/theme.vue b/packages/frontend/src/pages/settings/theme.vue
index d149849afc..adc93ff7a7 100644
--- a/packages/frontend/src/pages/settings/theme.vue
+++ b/packages/frontend/src/pages/settings/theme.vue
@@ -181,6 +181,12 @@ SPDX-License-Identifier: AGPL-3.0-only
 			</template>
 		</div>
 
+		<SearchMarker :keywords="['sync', 'themes', 'devices']">
+			<MkSwitch :modelValue="themesSyncEnabled" @update:modelValue="changeThemesSyncEnabled">
+				<template #label><SearchLabel>{{ i18n.ts._settings.enableSyncThemesBetweenDevices }}</SearchLabel></template>
+			</MkSwitch>
+		</SearchMarker>
+
 		<FormSection>
 			<div class="_formLinksGrid">
 				<FormLink to="/settings/theme/manage"><template #icon><i class="ti ti-tool"></i></template>{{ i18n.ts._theme.manage }}<template #suffix>{{ themesCount }}</template></FormLink>
@@ -264,6 +270,20 @@ watch(syncDeviceDarkMode, () => {
 	}
 });
 
+const themesSyncEnabled = ref(prefer.isSyncEnabled('themes'));
+
+function changeThemesSyncEnabled(value: boolean) {
+	if (value) {
+		prefer.enableSync('themes').then((res) => {
+			if (res == null) return;
+			if (res.enabled) themesSyncEnabled.value = true;
+		});
+	} else {
+		prefer.disableSync('themes');
+		themesSyncEnabled.value = false;
+	}
+}
+
 const headerActions = computed(() => []);
 
 const headerTabs = computed(() => []);
diff --git a/packages/frontend/src/utility/autogen/settings-search-index.ts b/packages/frontend/src/utility/autogen/settings-search-index.ts
index 08ab0d8811..7f800d2b70 100644
--- a/packages/frontend/src/utility/autogen/settings-search-index.ts
+++ b/packages/frontend/src/utility/autogen/settings-search-index.ts
@@ -37,6 +37,11 @@ export const searchIndexes: SearchIndexItem[] = [
 				label: i18n.ts.themeForDarkMode,
 				keywords: ['dark', 'theme'],
 			},
+			{
+				id: 'jwW5HULqA',
+				label: i18n.ts._settings.enableSyncThemesBetweenDevices,
+				keywords: ['sync', 'themes', 'devices'],
+			},
 		],
 		label: i18n.ts.theme,
 		keywords: ['theme'],