Jack Grimes (April 1, 1926 – March 10, 2009) was an American voice and radio actor who played Jimmy Olsen in the last three years of The Adventures of Superman radio program, and the 1966 Filmation TV series The New Adventures of Superman.

He is also known for his performance as the mechanic Sparky, and the pet chimp Chim-Chim in the 1967 anime Speed Racer.

[1] His acting career began at age seven during the Great Depression, when he helped earn money for his family.

He was also a regular on The Fred Allen Show, The Philip Morris Playhouse, Second Husband, CBS Radio Mystery Theater, and Death Valley Days.

Grimes notably appeared as the titular robot in the 05/13/1950 episode of Dimension X, entitled "Almost Human".