The Incredible Mr. Limpet is a 1964 American live-action/animated comedy film produced by Warner Bros. and based on the 1942 novel Mr. Limpet by Theodore Pratt. It is about a man named Henry Limpet who turns into a talking fish and helps the U.S. Navy locate and destroy Nazi submarines. Don Knotts plays the title character. The live action was directed by Arthur Lubin, while the animation was directed by Bill Tytla, Robert McKimson, Hawley Pratt, and Gerry Chiniquy at Warner Bros. Cartoons. Music includes songs by Sammy Fain, in collaboration with Harold Adamson, including "I Wish I Were a Fish", "Be Careful How You Wish" and "Deep Rapture". The film received mixed reviews. It was the final project for Warner Bros. Cartoons prior to its closure in May 1963.

Jesse Donald Knotts was an American actor and comedian. He is widely known for his role as Deputy Sheriff Barney Fife on the 1960s sitcom The Andy Griffith Show, for which he earned five Emmy Awards. He also played Ralph Furley on the highly rated sitcom Three's Company from 1979 to 1984. He starred in multiple comedic films, including leading roles in The Incredible Mr. Limpet (1964) and The Ghost and Mr. Chicken (1966). In 2004, TV Guide ranked him number 27 on its 50 Greatest TV Stars of All Time list.