The Australian actress will play the wife of rock star Atticus Fetch, played by fellow Australian actor Tim Minchin, reports Deadline.
The pair's storyline revolves around Fetch writing the music for the Broadway musical Crazy Little Thing Called Love.
The Broadway show is based on the show's popular romcom movie of the same name, which was adapted from Hank Moody's (David Duchovny) novel.
Wynter's television credits include 24, Damages, Army Wives and recently Person of Interest.
Californication recently ended its fifth season and will return for a sixth season.
Watch a promo video for Californication's season five below: