Rocket-Bye Baby is a 1956 Warner Bros. animated cartoon in the Merrie Melodies series, directed by Chuck Jones. The short was released on August 4, 1956.

The Michael Maltese story follows the adventures of a baby from Mars who ends up on Earth after the planets close to each other and create a 'cosmic force'. It was Warner Brothers' take on the borderline hysteria surrounding UFOs in the 1950s.

The cartoon is one of a very few Warner Brothers short films of the era that did not use Mel Blanc's voice talent. Instead, Daws Butler, famous for the voices of Yogi Bear, Huckleberry Hound and other characters in the Hanna-Barbera oeuvre, and June Foray, most famous as the voice of Rocky the Flying Squirrel, provided the vocal content of the short.

The title is a play on the nursery rhyme Rock-a-bye Baby.