diff --git a/locales/rn/et.json b/locales/rn/et.json
new file mode 100644
index 00000000..32b5ae5a
--- /dev/null
+++ b/locales/rn/et.json
@@ -0,0 +1,76 @@
+{
+  "calendar": {
+    "detail": {
+      "delete_confirm": "Kustutada see sündmus?"
+    }
+  },
+  "contacts": {
+    "bulk": {
+      "delete_confirm_title": "Kustuta kontaktid"
+    },
+    "delete_confirm_title": "Kustuta kontakt"
+  },
+  "email_viewer": {
+    "not_spam_short": "Pole rämpspost",
+    "spam_short": "Rämpspost"
+  },
+  "files": {
+    "batch_delete_confirm_message": "Kas oled kindel, et soovid kustutada {count, plural, one {1 üksuse} other {# üksust}}? Seda ei saa tagasi võtta.",
+    "batch_delete_success": "{count, plural, one {1 üksus kustutatud} other {# üksust kustutatud}}",
+    "delete_confirm_message": "Kas oled kindel, et soovid kustutada \"{name}\"? Seda ei saa tagasi võtta.",
+    "delete_confirm_title": "Kustuta ressurss",
+    "delete_success": "Edukalt kustutatud"
+  },
+  "settings": {
+    "composer": {
+      "autosave": {
+        "1m": "Iga minuti järel",
+        "2m": "Iga 2 minuti järel",
+        "30s": "Iga 30 sekundi järel",
+        "5m": "Iga 5 minuti järel",
+        "description": "Kui sageli mustandeid automaatselt salvestatakse",
+        "label": "Automaatsalvestuse intervall"
+      },
+      "description": "Seadista kirja koostamise sätteid",
+      "title": "Koostamine"
+    },
+    "email_behavior": {
+      "disable_threading": {
+        "description": "Kuva e-kirjad üksikute kirjadena vestluste kaupa rühmitamise asemel",
+        "label": "Keela vestluste rühmitamine"
+      }
+    },
+    "filters": {
+      "sieve_editor": {
+        "confirm_save": "Kinnita salvestamine",
+        "save_warning": "Salvestamine kirjutab kõik visuaalsed reeglid üle. Seda ei saa tagasi võtta. Kinnitamiseks klõpsa uuesti nuppu Salvesta."
+      }
+    },
+    "identities": {
+      "title": "Saatja identiteedid"
+    },
+    "notifications": {
+      "calendar": {
+        "invitation_parsing": "Tuvasta e-kirjade kutsed",
+        "invitation_parsing_desc": "Tuvasta kalendrikutsed e-kirjade manustest ja kuva kalenditoimingud"
+      }
+    },
+    "tab_groups": {
+      "advanced": "Täpsemalt",
+      "appearance": "Välimus",
+      "general": "Üldine",
+      "privacy": "Privaatsus ja turvalisus"
+    },
+    "tabs": {
+      "content_senders": "Sisu ja saatjad",
+      "downloads": "Allalaadimised",
+      "identities": "Identiteedid",
+      "keywords": "Sildid",
+      "language": "Keel, piirkond ja kellaaeg",
+      "layout": "Paigutus",
+      "sidebar_apps": "Külgriba rakendused",
+      "templates": "Mallid",
+      "themes": "Teemad"
+    }
+  }
+}
diff --git a/locales/rn/th.json b/locales/rn/th.json
new file mode 100644
index 00000000..0967ef42
--- /dev/null
+++ b/locales/rn/th.json
@@ -0,0 +1 @@
+{}
diff --git a/src/i18n/__tests__/locale.test.ts b/src/i18n/__tests__/locale.test.ts
index 7c4e7bde..acbb4b07 100644
--- a/src/i18n/__tests__/locale.test.ts
+++ b/src/i18n/__tests__/locale.test.ts
@@ -23,6 +23,11 @@ describe('resolveLocaleTag', () => {
     expect(resolveLocaleTag({ languageCode: 'nb', languageTag: 'nb-NO' })).toBe('nb');
   });
 
+  it('takes Thai and Estonian, which the webmail has too', () => {
+    expect(resolveLocaleTag({ languageCode: 'th', languageTag: 'th-TH' })).toBe('th');
+    expect(resolveLocaleTag({ languageCode: 'et', languageTag: 'et-EE' })).toBe('et');
+  });
+
   it('returns null for unsupported languages', () => {
     expect(resolveLocaleTag({ languageCode: 'xx', languageTag: 'xx-XX' })).toBeNull();
     expect(resolveLocaleTag({})).toBeNull();
@@ -40,6 +45,11 @@ describe('getLocaleDirection', () => {
 });
 
 describe('translate', () => {
+  it('reads Thai and Estonian from their own catalogs', () => {
+    expect(translate('th', 'settings.title')).not.toBe(translate('en', 'settings.title'));
+    expect(translate('et', 'settings.title')).not.toBe(translate('en', 'settings.title'));
+  });
+
   it('falls back locale → en → fallback → key', () => {
     expect(translate('de', 'settings.title')).not.toBe('settings.title');
     expect(translate('de', 'nope.missing', 'Fallback')).toBe('Fallback');
diff --git a/src/i18n/index.ts b/src/i18n/index.ts
index ed0a57d0..de22f929 100644
--- a/src/i18n/index.ts
+++ b/src/i18n/index.ts
@@ -30,6 +30,7 @@ export const SUPPORTED_LOCALES = [
   { code: 'da', label: 'Dansk' },
   { code: 'de', label: 'Deutsch' },
   { code: 'en', label: 'English' },
+  { code: 'et', label: 'Eesti' },
   { code: 'fa', label: 'فارسی' },
   { code: 'es', label: 'Español' },
   { code: 'fr', label: 'Français' },
@@ -42,6 +43,7 @@ export const SUPPORTED_LOCALES = [
   { code: 'pl', label: 'Polski' },
   { code: 'pt', label: 'Português' },
   { code: 'ro', label: 'Română' },
+  { code: 'th', label: 'ไทย' },
   { code: 'tr', label: 'Türkçe' },
   { code: 'ru', label: 'Русский' },
   { code: 'uk', label: 'Українська' },
@@ -74,7 +76,7 @@ function deepMerge(base: Dictionary, overlay: Dictionary): Dictionary {
 
 // A catalog is a few hundred KB of JSON. Metro only evaluates a module when it
 // is first required, so keeping each require inside its loader means startup
-// builds English plus the active language instead of all 27, and switching
+// builds English plus the active language instead of all 29, and switching
 // language loads the new catalog synchronously on the next t() call. The
 // require paths must stay string literals for Metro to bundle them.
 const CATALOG_LOADERS: Record<LocaleCode, () => Dictionary> = {
@@ -84,6 +86,7 @@ const CATALOG_LOADERS: Record<LocaleCode, () => Dictionary> = {
   da: () => require('../../locales/da/common.json'),
   de: () => require('../../locales/de/common.json'),
   en: () => en as Dictionary,
+  et: () => require('../../locales/et/common.json'),
   es: () => require('../../locales/es/common.json'),
   fa: () => require('../../locales/fa/common.json'),
   fr: () => require('../../locales/fr/common.json'),
@@ -100,6 +103,7 @@ const CATALOG_LOADERS: Record<LocaleCode, () => Dictionary> = {
   pt: () => require('../../locales/pt/common.json'),
   ro: () => require('../../locales/ro/common.json'),
   ru: () => require('../../locales/ru/common.json'),
+  th: () => require('../../locales/th/common.json'),
   sk: () => require('../../locales/sk/common.json'),
   tr: () => require('../../locales/tr/common.json'),
   uk: () => require('../../locales/uk/common.json'),
@@ -115,6 +119,7 @@ const OVERLAY_LOADERS: Record<LocaleCode, () => Dictionary> = {
   da: () => require('../../locales/rn/da.json'),
   de: () => require('../../locales/rn/de.json'),
   en: () => rnEn as Dictionary,
+  et: () => require('../../locales/rn/et.json'),
   es: () => require('../../locales/rn/es.json'),
   fa: () => require('../../locales/rn/fa.json'),
   fr: () => require('../../locales/rn/fr.json'),
@@ -131,6 +136,7 @@ const OVERLAY_LOADERS: Record<LocaleCode, () => Dictionary> = {
   pt: () => require('../../locales/rn/pt.json'),
   ro: () => require('../../locales/rn/ro.json'),
   ru: () => require('../../locales/rn/ru.json'),
+  th: () => require('../../locales/rn/th.json'),
   sk: () => require('../../locales/rn/sk.json'),
   tr: () => require('../../locales/rn/tr.json'),
   uk: () => require('../../locales/rn/uk.json'),
diff --git a/src/lib/calendar-locale.ts b/src/lib/calendar-locale.ts
index 3461cb23..5f857c66 100644
--- a/src/lib/calendar-locale.ts
+++ b/src/lib/calendar-locale.ts
@@ -19,6 +19,7 @@ const DATE_FNS_LOCALE_LOADERS: Record<LocaleCode, () => Locale> = {
   da: () => require('date-fns/locale/da').da,
   de: () => require('date-fns/locale/de').de,
   es: () => require('date-fns/locale/es').es,
+  et: () => require('date-fns/locale/et').et,
   fa: () => require('date-fns/locale/fa-IR').faIR,
   fr: () => require('date-fns/locale/fr').fr,
   he: () => require('date-fns/locale/he').he,
@@ -35,6 +36,7 @@ const DATE_FNS_LOCALE_LOADERS: Record<LocaleCode, () => Locale> = {
   ro: () => require('date-fns/locale/ro').ro,
   ru: () => require('date-fns/locale/ru').ru,
   sk: () => require('date-fns/locale/sk').sk,
+  th: () => require('date-fns/locale/th').th,
   tr: () => require('date-fns/locale/tr').tr,
   uk: () => require('date-fns/locale/uk').uk,
   zh: () => require('date-fns/locale/zh-CN').zhCN,