He is known for his role as Frank Fontana on the CBS television sitcom Murphy Brown, which earned him a Primetime Emmy Award nomination in 1989.

[2] After some bits and guest appearances, he had his first major role as attorney Elliot Streeter in the acclaimed but short-lived legal sitcom The Associates, which aired from 1979-80.

He starred in the CBS series Knots Landing in the 1984–1985 and 1985–1986 seasons as Harry Fisher, a man who takes possession of the Ewing twins illegally, which centered on the Black Market storyline.

In 1985, Regalbuto increased his household recognition when he guest starred as cab driver and high school friend, Don Eddie Rice, in the television series Magnum, P.I.

In 2002, he appeared on the final season (5th) of the Ally McBeal TV series, episode 10, "One Hundred Tears", as Harvey Hall, a man who believed he could fly, using wings of his own making.

Regalbuto returned to a revival series of Murphy Brown in 2018 along with former co-stars Candice Bergen, Faith Ford and Grant Shaud.