Jack Grimes was born April 1, 1926, in New York City. Being told by his teacher in the second grade that he had a beautiful speaking voice, little Jackie began supporting his family at the age of seven by acting in the Broadway play, Old Maid. He also began acting in radio programs, starting with Let's Pretend. He did other radio series, such as Fred Allen, Philip Morris Playhouse, and Death Valley Days. He began acting in movies in 1944 (coinciding with his graduation from high school), when he actually commuted by train from New York to Los Angeles to act in films at Universal, where he had a contract, and he did this for many years. He also acted in television
During the 1950s, he he acted in the few remaining radio shows that were on the air, most notable on X Minus One. After 1962, he began doing voicework for cartoons. A few years after this, he started a project with his childhood friend, Peter Fernandez, in which a Japanese cartoon was given a new script. That cartoon was Speed Racer. He did the parts of Sparky (a little boy) and Chin Chin (a chimpanzee).
Jack continued to act on TV. In 1974, CBS began broadcasting radio dramas again with their CBS Radio Mystery Theater (which was recorded in New York). Jack did at least 49 of those shows. He also acted on some of the other radio shows that were going on at that time.
He retired in 1978. He was not related to the politician by the same name.
Jack Grimes died in Queens, New York, on March 10, 2009.