Jack R. Keller was an American comic book artist best known for his 1950s and 1960s work on the Marvel Comics Western character Kid Colt, and for his later hot rod and racecar series at Charlton Comics.

Kid Colt is the name of two fictional characters appearing in American comic books published by Marvel Comics. The first is a cowboy whose adventures have taken place in numerous western-themed comic book series published by Marvel. The second is a cowboy-themed horse-like superhero. The character's first appearance was in Kid Colt #1.