Yes they are! Subtitle languages can be changed via the videos' toolbars:
Subtitles are currently available in the following languages:
- Arabic
- English
- Chinese (simplified)
- Chinese (traditional)
- French
- German
- Indonesian
- Italian
- Japanese
- Korean
- Polish
- Portuguese
- Russian
- Spanish
- Thai
- Turkish
- Vietnamese
Note: Subtitles cannot currently be downloaded with videos.