James Thomas Callahan (October 4, 1930 – August 3, 2007) was an American film and television actor who appeared in more than 120 films and television shows between 1959 and 2007. He is perhaps best known for portraying Walter Powell on the sitcom Charles in Charge from 1987 to 1990.

He is seen as Powell in the opening theme of Charles in Charge in "New Kidney in Town". His credit scene was not shown, but was in the scene with his castmates.