Jack Deam (born Ian Deam; 1972) is an English actor. He used his grandfather's name for his stage name. His most notable performances have been as the pyromaniac Marty Fisher, who has Tourette syndrome, in Channel 4's comedy drama series, Shameless, and as Inspector Mallory in Father Brown (2013 TV series). In 1990, Deam appeared in the Granada TV soap opera Families, a show about two families, one from Cheshire, the other in Australia, notably alongside the then-not-so-well-known Jude Law. From 2010 to 2016, he played the part of a detective constable in the DCI Banks series.