He changed his professional name to his birth name Robin Thomas Grossman in 2014 but returned to "Robin Thomas" in 2015. Thomas" best-known television roles are as Mark Singleton in Another World (1983-1985), and as Geoffrey Wells on Who"s the Boss?. He had recurring roles in series such as Murphy Brown, Matlock, Life Unexpected, and The Division.
He appeared in such films as Pacific Rim, About Last Night.., The Contender, Summer School, and The Banger Sisters.
He has appeared in such television series as Misfits of Science, Midnight Caller, Party of Five, Pacific Blue, Queer as Folk, Murphy Brown, Life Unexpected, NCIS, NCIS: Los Angeles, Computer Society of India, Computer Society of India:Miami, Computer Society of India:New York, Criminal Minds, Franklin & Bash, Castle, "Manhattan", "Fuller House", among others