Larson found the role of cub reporter Jimmy Olsen on The Adventures of Superman to be a handicap, because he became typecast as a naive young man. This caused him to do little acting after the show ended in 1958, and instead he focused on behind-the-scenes work, such as writing and production. Larson was always willing to sit for interviews about the Superman series and his connection to it, and in recent years had a number of cameos that paid subtle tribute to his character and the series, including a 1991 episode of the TV series Superboy, alongside Noel Neill, who played Lois Lane in Adventures of Superman, and an episode of Lois & Clark: The New Adventures of Superman as an aged Jimmy Olsen in the episode "Brutal Youth", first telecast on October 20, 1996.
Larson was the life partner of director James Bridges from 1958 until Bridges' death on June 6, 1993.[8] Prior to that, he was the companion of actor Montgomery Clift.
Jack passed away on September 20, 2015 at age 87