John Karlen (born John Adam Karlewicz) was an American character actor who played multiple roles (Willie Loomis, Carl Collins, William H. Loomis, Desmond Collins, Alex Jenkins, and Kendrick Young) on the ABC serial Dark Shadows, in various episodes which aired from 1966 to 1971. Karlen also played Harvey Lacey, husband of Mary Beth Lacey (played by Tyne Daly), on the CBS crime series Cagney & Lacey (1982–88).