Gilles Marini

Gilles Marini has been cast on Switched at Birth, TVGuide.com has learned exclusively. He'll join the ABC Family series as Bay's birth father, Angelo.

Switched at Birth follows Bay (Vanessa Marano) and Daphne (Katie Leclerc), teenagers from different walks of life who have learned they're living with the wrong family. Bay, who comes from a privileged background, is really the daughter of single mother Regina (Constance Marie) while Daphne, who is hearing-impaired, is actually the child of Kathryn(Lea Thompson) and John (D.W. Moffett).

Switched at Birth star hopes to bridge the gap between the hearing and deaf communities

Marini, who recently played Luc on ABC's Brothers & Sisters, begins shooting his episode next week. It will air as the season finale on Monday, Aug. 8.

Switched at Birth debuted earlier this month as ABC Family's most-watched series premiere ever with 3.3 million viewers.