Boyd Gaines (born May 11, 1953) is an American award-winning stage, film and television actor. He has received three Tony Awards for his work. Gaines was born in Atlanta, Georgia, the son of Ida and James Gaines. He has also appeared in a number of films and television shows, including Fame, L.A. Law and Law & Order, but perhaps he is best known for playing a dental student and dentist Mark Royer, who married Valerie Bertinelli's Barbara Cooper on One Day at a Time. Gaines is a voice-actor, and is credited with several audiobook.