One Froggy Evening is a 1955 American Technicolor animated musical short film written by Michael Maltese and directed by Chuck Jones, with musical direction by Milt Franklyn. The short, partly inspired by a 1944 Cary Grant film entitled Once Upon a Time involving a dancing caterpillar in a small box, marks the debut of Michigan J. Frog: an anthropomorphic frog with a talent for singing and dancing that he demonstrates for no one except whoever possesses the box wherein he resides. This popular short contained a wide variety of musical entertainment, with songs ranging from "Hello! Ma Baby" and "I'm Just Wild About Harry", two Tin Pan Alley classics, to "Largo al Factotum", Figaro's aria from the opera Il Barbiere di Siviglia. The short was released on December 31, 1955, as part of Warner Bros.' Merrie Melodies series of cartoons.

In 1994, it was voted No. 5 of The 50 Greatest Cartoons of all time by members of the animation field. In 2003, the United States Library of Congress deemed the film "culturally, historically, or aesthetically significant", and selected it for preservation in the National Film Registry.

The film is included in the Looney Tunes Golden Collection: Volume 2 DVD box set (Disc 4), along with an audio commentary, optional music-only audio track (only the instrumental, not the vocal), and a making-of documentary, It Hopped One Night: A Look at "One Froggy Evening". It was also featured on the VHS release of Little Giants.