diff --git a/changes/youtube-primary-subtitle-config.md b/changes/youtube-primary-subtitle-config.md
new file mode 100644
index 0000000..dca64da
--- /dev/null
+++ b/changes/youtube-primary-subtitle-config.md
@@ -0,0 +1,5 @@
+type: changed
+area: launcher
+
+Moved YouTube primary subtitle language defaults to `youtube.primarySubLanguages`.
+Removed the old `youtubeSubgen.primarySubLanguages` config path from the generated config and docs.
diff --git a/config.example.jsonc b/config.example.jsonc
index b94e0c2..2f5c223 100644
--- a/config.example.jsonc
+++ b/config.example.jsonc
@@ -417,20 +417,11 @@
   // YouTube Playback Settings
   // Defaults for SubMiner YouTube subtitle loading and languages.
   // ==========================================
-  "youtubeSubgen": {
-    "whisperBin": "", // Legacy compatibility path kept for external subtitle fallback tools; not used by default.
-    "whisperModel": "", // Legacy compatibility model path kept for external subtitle fallback tooling; not used by default.
-    "whisperVadModel": "", // Legacy compatibility VAD path kept for external subtitle fallback tooling; not used by default.
-    "whisperThreads": 4, // Legacy thread tuning for subtitle fallback tooling; not used by default.
-    "fixWithAi": false, // Legacy subtitle fallback post-processing switch kept for compatibility; use is currently disabled by default. Values: true | false
-    "ai": {
-      "model": "", // Optional model override for legacy subtitle fallback post-processing; not used by default.
-      "systemPrompt": "" // Optional system prompt override for legacy subtitle fallback post-processing; not used by default.
-    }, // Ai setting.
+  "youtube": {
     "primarySubLanguages": [
       "ja",
       "jpn"
-    ] // Comma-separated primary subtitle language priority used by the launcher.
+    ] // Comma-separated primary subtitle language priority for YouTube auto-loading.
   }, // Defaults for SubMiner YouTube subtitle loading and languages.
 
   // ==========================================
diff --git a/launcher/config-domain-parsers.test.ts b/launcher/config-domain-parsers.test.ts
index 4f3f090..cc3ddfa 100644
--- a/launcher/config-domain-parsers.test.ts
+++ b/launcher/config-domain-parsers.test.ts
@@ -29,6 +29,8 @@ test('parseLauncherYoutubeSubgenConfig keeps only valid typed values', () => {
         model: 'openrouter/subgen-model',
         systemPrompt: 'Fix subtitles only.',
       },
+    },
+    youtube: {
       primarySubLanguages: ['ja', 42, 'en'],
     },
     secondarySub: {
diff --git a/launcher/config/youtube-subgen-config.ts b/launcher/config/youtube-subgen-config.ts
index eb1ecbd..3ed2e58 100644
--- a/launcher/config/youtube-subgen-config.ts
+++ b/launcher/config/youtube-subgen-config.ts
@@ -14,6 +14,9 @@ export function parseLauncherYoutubeSubgenConfig(
     youtubeSubgenRaw && typeof youtubeSubgenRaw === 'object'
       ? (youtubeSubgenRaw as Record<string, unknown>)
       : null;
+  const youtubeRaw = root.youtube;
+  const youtube =
+    youtubeRaw && typeof youtubeRaw === 'object' ? (youtubeRaw as Record<string, unknown>) : null;
   const secondarySubRaw = root.secondarySub;
   const secondarySub =
     secondarySubRaw && typeof secondarySubRaw === 'object'
@@ -74,7 +77,7 @@ export function parseLauncherYoutubeSubgenConfig(
           }
         : undefined,
     ),
-    primarySubLanguages: asStringArray(youtubeSubgen?.primarySubLanguages),
+    primarySubLanguages: asStringArray(youtube?.primarySubLanguages),
     secondarySubLanguages: asStringArray(secondarySub?.secondarySubLanguages),
     jimakuApiKey: typeof jimaku?.apiKey === 'string' ? jimaku.apiKey : undefined,
     jimakuApiKeyCommand:
diff --git a/src/config/config.test.ts b/src/config/config.test.ts
index f9f8212..ada4876 100644
--- a/src/config/config.test.ts
+++ b/src/config/config.test.ts
@@ -919,7 +919,7 @@ test('accepts trailing commas in jsonc', () => {
         "enabled": "auto",
         "port": 7788,
       },
-      "youtubeSubgen": {
+      "youtube": {
         "primarySubLanguages": ["ja", "en",],
       },
     }`,
@@ -929,7 +929,7 @@ test('accepts trailing commas in jsonc', () => {
   const service = new ConfigService(dir);
   const config = service.getConfig();
   assert.equal(config.websocket.port, 7788);
-  assert.deepEqual(config.youtubeSubgen.primarySubLanguages, ['ja', 'en']);
+  assert.deepEqual(config.youtube.primarySubLanguages, ['ja', 'en']);
 });
 
 test('reloadConfigStrict rejects invalid jsonc and preserves previous config', () => {
@@ -1149,8 +1149,10 @@ test('parses global shortcuts and startup settings', () => {
         "toggleVisibleOverlayGlobal": "Alt+Shift+U",
         "openJimaku": "Ctrl+Alt+J"
       },
+      "youtube": {
+        "primarySubLanguages": ["ja", "jpn", "jp"]
+      },
       "youtubeSubgen": {
-        "primarySubLanguages": ["ja", "jpn", "jp"],
         "whisperVadModel": "/models/vad.bin",
         "whisperThreads": 12,
         "fixWithAi": true
@@ -1165,7 +1167,7 @@ test('parses global shortcuts and startup settings', () => {
   assert.equal(config.ai.apiKeyCommand, 'pass show subminer/ai');
   assert.equal(config.shortcuts.toggleVisibleOverlayGlobal, 'Alt+Shift+U');
   assert.equal(config.shortcuts.openJimaku, 'Ctrl+Alt+J');
-  assert.deepEqual(config.youtubeSubgen.primarySubLanguages, ['ja', 'jpn', 'jp']);
+  assert.deepEqual(config.youtube.primarySubLanguages, ['ja', 'jpn', 'jp']);
   assert.equal(config.youtubeSubgen.whisperVadModel, '/models/vad.bin');
   assert.equal(config.youtubeSubgen.whisperThreads, 12);
   assert.equal(config.youtubeSubgen.fixWithAi, true);
@@ -2008,7 +2010,8 @@ test('template generator includes known keys', () => {
   assert.match(output, /"websocket":/);
   assert.match(output, /"discordPresence":/);
   assert.match(output, /"startupWarmups":/);
-  assert.match(output, /"youtubeSubgen":/);
+  assert.match(output, /"youtube":/);
+  assert.doesNotMatch(output, /"youtubeSubgen":/);
   assert.match(output, /"characterDictionary":\s*\{/);
   assert.match(output, /"preserveLineBreaks": false/);
   assert.match(output, /"knownWords"\s*:\s*\{/);
@@ -2074,17 +2077,11 @@ test('template generator includes known keys', () => {
   );
   assert.match(
     output,
-    /"fixWithAi": false,? \/\/ Legacy subtitle fallback post-processing switch kept for compatibility; use is currently disabled by default\. Values: true \| false/,
-  );
-  assert.match(
-    output,
-    /"systemPrompt": "",? \/\/ Optional system prompt override for legacy subtitle fallback post-processing; not used by default\./,
+    /"primarySubLanguages": \[\s*"ja",\s*"jpn"\s*\],? \/\/ Comma-separated primary subtitle language priority for YouTube auto-loading\./,
   );
   assert.doesNotMatch(output, /"mode": "automatic"/);
-  assert.match(
-    output,
-    /"whisperThreads": 4,? \/\/ Legacy thread tuning for subtitle fallback tooling; not used by default\./,
-  );
+  assert.doesNotMatch(output, /"fixWithAi": false/);
+  assert.doesNotMatch(output, /"whisperThreads": 4/);
   assert.match(
     output,
     /"launchAtStartup": true,? \/\/ Launch texthooker server automatically when SubMiner starts\. Values: true \| false/,
diff --git a/src/config/definitions.ts b/src/config/definitions.ts
index 59c4f99..0692e66 100644
--- a/src/config/definitions.ts
+++ b/src/config/definitions.ts
@@ -30,6 +30,7 @@ const {
   controller,
   shortcuts,
   secondarySub,
+  youtube,
   subsync,
   startupWarmups,
   auto_start_overlay,
@@ -51,6 +52,7 @@ export const DEFAULT_CONFIG: ResolvedConfig = {
   ankiConnect,
   shortcuts,
   secondarySub,
+  youtube,
   subsync,
   startupWarmups,
   subtitleStyle,
diff --git a/src/config/definitions/defaults-core.ts b/src/config/definitions/defaults-core.ts
index af11bc8..4d42915 100644
--- a/src/config/definitions/defaults-core.ts
+++ b/src/config/definitions/defaults-core.ts
@@ -11,6 +11,7 @@ export const CORE_DEFAULT_CONFIG: Pick<
   | 'controller'
   | 'shortcuts'
   | 'secondarySub'
+  | 'youtube'
   | 'subsync'
   | 'startupWarmups'
   | 'auto_start_overlay'
@@ -93,6 +94,9 @@ export const CORE_DEFAULT_CONFIG: Pick<
     autoLoadSecondarySub: false,
     defaultMode: 'hover',
   },
+  youtube: {
+    primarySubLanguages: ['ja', 'jpn'],
+  },
   subsync: {
     defaultMode: 'auto',
     alass_path: '',
diff --git a/src/config/definitions/defaults-integrations.ts b/src/config/definitions/defaults-integrations.ts
index d6074d7..761a2e0 100644
--- a/src/config/definitions/defaults-integrations.ts
+++ b/src/config/definitions/defaults-integrations.ts
@@ -152,6 +152,5 @@ export const INTEGRATIONS_DEFAULT_CONFIG: Pick<
       model: '',
       systemPrompt: '',
     },
-    primarySubLanguages: ['ja', 'jpn'],
   },
 };
diff --git a/src/config/definitions/domain-registry.test.ts b/src/config/definitions/domain-registry.test.ts
index 8051e73..4bc079f 100644
--- a/src/config/definitions/domain-registry.test.ts
+++ b/src/config/definitions/domain-registry.test.ts
@@ -22,6 +22,7 @@ test('config option registry includes critical paths and has unique entries', ()
     'controller.enabled',
     'controller.scrollPixelsPerSecond',
     'startupWarmups.lowPowerMode',
+    'youtube.primarySubLanguages',
     'subtitleStyle.enableJlpt',
     'subtitleStyle.autoPauseVideoOnYomitanPopup',
     'ankiConnect.enabled',
@@ -43,6 +44,7 @@ test('config template sections include expected domains and unique keys', () =>
     'annotationWebsocket',
     'controller',
     'startupWarmups',
+    'youtube',
     'subtitleStyle',
     'ankiConnect',
     'yomitan',
diff --git a/src/config/definitions/options-core.ts b/src/config/definitions/options-core.ts
index 8f50a7f..1ab1fd4 100644
--- a/src/config/definitions/options-core.ts
+++ b/src/config/definitions/options-core.ts
@@ -83,6 +83,12 @@ export function buildCoreConfigOptionRegistry(
       defaultValue: defaultConfig.logging.level,
       description: 'Minimum log level for runtime logging.',
     },
+    {
+      path: 'youtube.primarySubLanguages',
+      kind: 'string',
+      defaultValue: defaultConfig.youtube.primarySubLanguages.join(','),
+      description: 'Comma-separated primary subtitle language priority for YouTube auto-loading.',
+    },
     {
       path: 'controller.enabled',
       kind: 'boolean',
diff --git a/src/config/definitions/options-integrations.ts b/src/config/definitions/options-integrations.ts
index 3656091..ff5feff 100644
--- a/src/config/definitions/options-integrations.ts
+++ b/src/config/definitions/options-integrations.ts
@@ -411,11 +411,5 @@ export function buildIntegrationConfigOptionRegistry(
       description:
         'Optional system prompt override for legacy subtitle fallback post-processing; not used by default.',
     },
-    {
-      path: 'youtubeSubgen.primarySubLanguages',
-      kind: 'string',
-      defaultValue: defaultConfig.youtubeSubgen.primarySubLanguages.join(','),
-      description: 'Comma-separated primary subtitle language priority used by the launcher.',
-    },
   ];
 }
diff --git a/src/config/definitions/template-sections.ts b/src/config/definitions/template-sections.ts
index 8be0158..b2918db 100644
--- a/src/config/definitions/template-sections.ts
+++ b/src/config/definitions/template-sections.ts
@@ -132,7 +132,7 @@ const INTEGRATION_TEMPLATE_SECTIONS: ConfigTemplateSection[] = [
   {
     title: 'YouTube Playback Settings',
     description: ['Defaults for SubMiner YouTube subtitle loading and languages.'],
-    key: 'youtubeSubgen',
+    key: 'youtube',
   },
   {
     title: 'Anilist',
diff --git a/src/config/resolve/core-domains.ts b/src/config/resolve/core-domains.ts
index feac20c..9920e7e 100644
--- a/src/config/resolve/core-domains.ts
+++ b/src/config/resolve/core-domains.ts
@@ -524,6 +524,21 @@ export function applyCoreDomainConfig(context: ResolveContext): void {
     }
   }
 
+  if (isObject(src.youtube)) {
+    if (Array.isArray(src.youtube.primarySubLanguages)) {
+      resolved.youtube.primarySubLanguages = src.youtube.primarySubLanguages.filter(
+        (item): item is string => typeof item === 'string',
+      );
+    } else if (src.youtube.primarySubLanguages !== undefined) {
+      warn(
+        'youtube.primarySubLanguages',
+        src.youtube.primarySubLanguages,
+        resolved.youtube.primarySubLanguages,
+        'Expected string array.',
+      );
+    }
+  }
+
   if (isObject(src.subsync)) {
     const mode = src.subsync.defaultMode;
     if (mode === 'auto' || mode === 'manual') {
diff --git a/src/config/resolve/subtitle-domains.ts b/src/config/resolve/subtitle-domains.ts
index 2d88bb6..81d77d1 100644
--- a/src/config/resolve/subtitle-domains.ts
+++ b/src/config/resolve/subtitle-domains.ts
@@ -135,16 +135,12 @@ export function applySubtitleDomainConfig(context: ResolveContext): void {
       warn('youtubeSubgen.ai', src.youtubeSubgen.ai, resolved.youtubeSubgen.ai, 'Expected object.');
     }
 
-    if (Array.isArray(src.youtubeSubgen.primarySubLanguages)) {
-      resolved.youtubeSubgen.primarySubLanguages = src.youtubeSubgen.primarySubLanguages.filter(
-        (item): item is string => typeof item === 'string',
-      );
-    } else if (src.youtubeSubgen.primarySubLanguages !== undefined) {
+    if (src.youtubeSubgen.primarySubLanguages !== undefined) {
       warn(
         'youtubeSubgen.primarySubLanguages',
         src.youtubeSubgen.primarySubLanguages,
-        resolved.youtubeSubgen.primarySubLanguages,
-        'Expected string array.',
+        undefined,
+        'Removed. Use youtube.primarySubLanguages instead.',
       );
     }
   }
diff --git a/src/main.ts b/src/main.ts
index dc8b865..51b9ae6 100644
--- a/src/main.ts
+++ b/src/main.ts
@@ -1337,7 +1337,7 @@ const startupOsdSequencer = createStartupOsdSequencer({
   showOsd: (message) => showMpvOsd(message),
 });
 const youtubePrimarySubtitleNotificationRuntime = createYoutubePrimarySubtitleNotificationRuntime({
-  getPrimarySubtitleLanguages: () => getResolvedConfig().youtubeSubgen.primarySubLanguages,
+  getPrimarySubtitleLanguages: () => getResolvedConfig().youtube.primarySubLanguages,
   notifyFailure: (message) => reportYoutubeSubtitleFailure(message),
   schedule: (fn, delayMs) => setTimeout(fn, delayMs),
   clearSchedule: clearYoutubePrimarySubtitleNotificationTimer,
diff --git a/src/types.ts b/src/types.ts
index c80da93..61e30ca 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -683,6 +683,10 @@ export interface AiConfig {
   requestTimeoutMs?: number;
 }
 
+export interface YoutubeConfig {
+  primarySubLanguages?: string[];
+}
+
 export interface YoutubeSubgenConfig {
   whisperBin?: string;
   whisperModel?: string;
@@ -690,7 +694,6 @@ export interface YoutubeSubgenConfig {
   whisperThreads?: number;
   fixWithAi?: boolean;
   ai?: AiFeatureConfig;
-  primarySubLanguages?: string[];
 }
 
 export interface StatsConfig {
@@ -750,6 +753,7 @@ export interface Config {
   jellyfin?: JellyfinConfig;
   discordPresence?: DiscordPresenceConfig;
   ai?: AiConfig;
+  youtube?: YoutubeConfig;
   youtubeSubgen?: YoutubeSubgenConfig;
   immersionTracking?: ImmersionTrackingConfig;
   stats?: StatsConfig;
@@ -929,6 +933,9 @@ export interface ResolvedConfig {
     systemPrompt: string;
     requestTimeoutMs: number;
   };
+  youtube: YoutubeConfig & {
+    primarySubLanguages: string[];
+  };
   youtubeSubgen: YoutubeSubgenConfig & {
     whisperBin: string;
     whisperModel: string;
@@ -936,7 +943,6 @@ export interface ResolvedConfig {
     whisperThreads: number;
     fixWithAi: boolean;
     ai: AiFeatureConfig;
-    primarySubLanguages: string[];
   };
   immersionTracking: {
     enabled: boolean;