Jon Alexander "Jack" Douglas (September 10, 1936 – July 27, 2010)[1] was an amateur American tennis player and college football quarterback.

[1] He graduated from Santa Monica High School, where he played football, tennis, and basketball.

After graduating from Stanford, Douglas entered top-level competitive amateur tennis.

[2] He won the singles title at the inaugural Philadelphia Invitational Indoor Tennis Championship in 1962, defeating Ronald Holmberg in the final in five sets.

He scored the only point for the U.S. by defeating Fausto Gardini in five sets, as they lost the 1961 Davis Cup finals to host country Italy.