diff --git a/speech_to_text/lib/speech_to_text.dart b/speech_to_text/lib/speech_to_text.dart
index 195c8e9..2a2a6aa 100644
--- a/speech_to_text/lib/speech_to_text.dart
+++ b/speech_to_text/lib/speech_to_text.dart
@@ -19,6 +19,16 @@ class LocaleName {
   final String name;
 
   LocaleName(this.localeId, this.name);
+
+  @override
+  bool operator ==(dynamic other) {
+    if (other.runtimeType != runtimeType) return false;
+    final LocaleName typedOther = other;
+    return this.localeId == typedOther.localeId;
+  }
+
+  @override
+  int get hashCode => localeId.hashCode;
 }
 
 /// Notified as words are recognized with the current set of recognized words.
@@ -578,6 +588,7 @@ class SpeechToText {
           return LocaleName(components[0], components[1]);
         })
         .where((item) => item != null)
+        .toSet()
         .toList()
         .cast<LocaleName>();
     if (filteredLocales.isNotEmpty) {
diff --git a/speech_to_text/test/speech_to_text_test.dart b/speech_to_text/test/speech_to_text_test.dart
index 450aa67..5cea330 100644
--- a/speech_to_text/test/speech_to_text_test.dart
+++ b/speech_to_text/test/speech_to_text_test.dart
@@ -558,6 +558,20 @@ void main() {
       expect(localeNames[1].localeId, TestSpeechChannelHandler.localeId2);
       expect(localeNames[1].name, TestSpeechChannelHandler.name2);
     });
+    test('deduplicates returned locales', () async {
+      await speech.initialize();
+      testPlatform.localesResult.addAll([
+        TestSpeechChannelHandler.locale1,
+        TestSpeechChannelHandler.locale2,
+        TestSpeechChannelHandler.locale1
+      ]);
+      var localeNames = await speech.locales();
+      expect(localeNames, hasLength(2));
+      expect(localeNames[0].localeId, TestSpeechChannelHandler.localeId1);
+      expect(localeNames[0].name, TestSpeechChannelHandler.name1);
+      expect(localeNames[1].localeId, TestSpeechChannelHandler.localeId2);
+      expect(localeNames[1].name, TestSpeechChannelHandler.name2);
+    });
     test('skips incorrect locales', () async {
       await speech.initialize();
       testPlatform.localesResult.addAll([