diff --git a/package.json b/package.json
index 24a07d6..702d8ff 100644
--- a/package.json
+++ b/package.json
@@ -79,7 +79,7 @@
       {"from": "runtime/models/whisper-base.json", "to": "manifests/model-manifest.json"}
     ],
     "win": {"target": "nsis"},
-    "mac": {"target": "dmg", "icon": "build/icon.icns"},
+    "mac": {"target": "dmg", "icon": "build/icon.icns", "electronLanguages": ["en", "en_GB", "es", "es_419"]},
     "linux": {"target": "AppImage"}
   }
 }
diff --git a/scripts/check-packaged-electron-locales.js b/scripts/check-packaged-electron-locales.js
new file mode 100644
index 0000000..082663f
--- /dev/null
+++ b/scripts/check-packaged-electron-locales.js
@@ -0,0 +1,95 @@
+#!/usr/bin/env node
+
+const fs = require('fs');
+const path = require('path');
+const packageJson = require('../package.json');
+const { newestApp } = require('./check-packaged-runtime');
+
+const root = path.join(__dirname, '..');
+
+function optionValue(name) {
+  const index = process.argv.indexOf(name);
+  return index >= 0 ? process.argv[index + 1] : undefined;
+}
+
+function fail(message) {
+  throw new Error(`Packaged Electron locale check failed: ${message}`);
+}
+
+function configuredLanguages() {
+  const languages = packageJson.build?.mac?.electronLanguages;
+  if (!Array.isArray(languages) || languages.length === 0) {
+    fail('package.json build.mac.electronLanguages must be a non-empty array');
+  }
+  const normalized = languages.map((language) => String(language).trim()).filter(Boolean);
+  if (normalized.length !== languages.length || new Set(normalized).size !== normalized.length) {
+    fail('package.json build.mac.electronLanguages contains an empty or duplicate locale');
+  }
+  return normalized;
+}
+
+function localeDirectories(directory) {
+  if (!fs.existsSync(directory) || !fs.statSync(directory).isDirectory()) {
+    fail(`locale resource directory is missing: ${path.relative(root, directory)}`);
+  }
+  return fs.readdirSync(directory, { withFileTypes: true })
+    .filter((entry) => entry.isDirectory() && entry.name.endsWith('.lproj'))
+    .map((entry) => entry.name.slice(0, -'.lproj'.length))
+    .sort();
+}
+
+function inspectLocaleRoot(directory, allowedLanguages, { requireAll = false } = {}) {
+  const locales = localeDirectories(directory);
+  const allowed = new Set(allowedLanguages.map((language) => language.toLowerCase()));
+  const unexpected = locales.filter((locale) => !allowed.has(locale.toLowerCase()));
+  if (unexpected.length > 0) {
+    fail(`${path.relative(root, directory)} contains unexpected Electron locales: ${unexpected.join(', ')}`);
+  }
+  if (requireAll) {
+    const present = new Set(locales.map((locale) => locale.toLowerCase()));
+    const missing = allowedLanguages.filter((language) => !present.has(language.toLowerCase()));
+    if (missing.length > 0) {
+      fail(`${path.relative(root, directory)} is missing configured Electron locales: ${missing.join(', ')}`);
+    }
+  }
+  return locales;
+}
+
+function inspectPackage(appPath) {
+  const allowedLanguages = configuredLanguages();
+  const resourcesPath = path.join(appPath, 'Contents', 'Resources');
+  const frameworkResourcesPath = path.join(
+    appPath,
+    'Contents',
+    'Frameworks',
+    'Electron Framework.framework',
+    'Versions',
+    'A',
+    'Resources',
+  );
+  const appLocales = inspectLocaleRoot(resourcesPath, allowedLanguages);
+  const frameworkLocales = inspectLocaleRoot(frameworkResourcesPath, allowedLanguages, { requireAll: true });
+  console.log(`Configured Electron locales: ${allowedLanguages.join(', ')}`);
+  console.log(`App resource locales: ${appLocales.join(', ') || 'none'}`);
+  console.log(`Electron Framework locales: ${frameworkLocales.join(', ')}`);
+  console.log('Packaged Electron locale check passed.');
+  return { appPath, allowedLanguages, appLocales, frameworkLocales };
+}
+
+function main() {
+  if (process.platform !== 'darwin') fail(`requires macOS, received ${process.platform}`);
+  const appPath = optionValue('--app') ? path.resolve(optionValue('--app')) : newestApp('arm64');
+  if (!appPath.endsWith('.app') || !fs.existsSync(appPath)) fail(`app does not exist: ${appPath}`);
+  return inspectPackage(appPath);
+}
+
+if (require.main === module) {
+  try {
+    main();
+  } catch (error) {
+    console.error(error instanceof Error ? error.message : String(error));
+    process.exit(1);
+  }
+}
+
+module.exports = { configuredLanguages, inspectPackage };
diff --git a/scripts/check-release-workflow.js b/scripts/check-release-workflow.js
index 9f2c527..8cc21d0 100644
--- a/scripts/check-release-workflow.js
+++ b/scripts/check-release-workflow.js
@@ -229,11 +229,19 @@ function main() {
   assert(/entitlementsInherit:\s*['"]build\/entitlements\.mac\.inherit\.plist['"]/.test(signedReleaseConfig), 'signed release config must set inherited entitlements');
   assert(!/identity:\s*['"]-['"]/.test(signedReleaseConfig), 'signed release config must not use ad-hoc identity');
   const packageText = fs.readFileSync(path.join(root, 'package.json'), 'utf8');
+  const packageJson = JSON.parse(packageText);
+  assert(
+    JSON.stringify(packageJson.build?.mac?.electronLanguages) === JSON.stringify(['en', 'en_GB', 'es', 'es_419']),
+    'macOS Electron locale allowlist must remain en/en_GB/es/es_419',
+  );
+  const releaseAlphaScript = fs.readFileSync(releaseAlphaPath, 'utf8');
+  assert(releaseAlphaScript.includes('check-packaged-electron-locales.js'), 'candidate release path is missing packaged Electron locale gate');
   assert(/release:signed:arm64/.test(packageText) && /scripts\/release-signed\.js/.test(packageText), 'signed release command is missing');
   assert(/check:signed-release/.test(packageText) && /check-macos-signed-release\.js/.test(packageText), 'signed release verification command is missing');
   const signedReleaseScript = fs.readFileSync(path.join(root, 'scripts', 'release-signed.js'), 'utf8');
   for (const requiredGate of [
     'check-packaged-runtime.js',
+    'check-packaged-electron-locales.js',
     'smoke-packaged-release-identity.js',
     'check-packaged-ffmpeg.js',
     'smoke-packaged-backend.js',
diff --git a/scripts/release-alpha.js b/scripts/release-alpha.js
index c667887..4093ea1 100644
--- a/scripts/release-alpha.js
+++ b/scripts/release-alpha.js
@@ -306,6 +306,7 @@ async function main() {
   const outputs = candidateOutputs(pkg);
   const packageInfo = inspectPackage(outputs.appPath);
   runPackagedGate('Packaged runtime gate', 'scripts/check-packaged-runtime.js', ['--arch', 'arm64', '--app', outputs.appPath], env);
+  runPackagedGate('Packaged Electron locale gate', 'scripts/check-packaged-electron-locales.js', ['--app', outputs.appPath], env);
   runPackagedGate('Packaged release identity gate', 'scripts/smoke-packaged-release-identity.js', ['--app', outputs.appPath], env);
   runPackagedGate('Packaged FFmpeg gate', 'scripts/check-packaged-ffmpeg.js', ['--arch', 'arm64', '--app', outputs.appPath], env);
   runPackagedGate('Packaged backend gate', 'scripts/smoke-packaged-backend.js', ['--arch', 'arm64', '--app', outputs.appPath], env);
diff --git a/scripts/release-signed.js b/scripts/release-signed.js
index e0150c0..abe2422 100644
--- a/scripts/release-signed.js
+++ b/scripts/release-signed.js
@@ -45,6 +45,7 @@ function main() {
   const appPath = path.join(outputRoot, 'mac-arm64', 'ScriptCut.app');
   const dmgPath = path.join(outputRoot, `ScriptCut-${version}-arm64.dmg`);
   run('Packaged runtime gate', 'node', ['scripts/check-packaged-runtime.js', '--arch', 'arm64', '--app', appPath]);
+  run('Packaged Electron locale gate', 'node', ['scripts/check-packaged-electron-locales.js', '--app', appPath]);
   run('Packaged release identity gate', 'node', ['scripts/smoke-packaged-release-identity.js', '--app', appPath]);
   run('Packaged FFmpeg gate', 'node', ['scripts/check-packaged-ffmpeg.js', '--arch', 'arm64', '--app', appPath]);
   run('Packaged backend gate', 'node', ['scripts/smoke-packaged-backend.js', '--arch', 'arm64', '--app', appPath]);