Vak or Vac IPA [va:c] (stem vāc-, nominative vāk) is the Sanskrit word for "speech", "voice", "talk", or "language".

Personified, Vak is a goddess, most frequently she is identified with Bharati or Sarasvati, the goddess of speech. In the Veda she is also represented as created by Prajapati and married to him; in other places she is called the mother of the Vedas and wife of Indra.