A person who translates written text from one language to another. For oral translation, 通訳者 (つうやくしゃ) is used.
She translates novels as a professional translator.
I had a translator put this contract into English.
Compound of 翻訳 (ほんやく, 'translation') + 者 (しゃ, 'person'). The word 翻訳 is itself composed of 翻 (turn over, change) and 訳 (translate).