The What-a-Cartoon! Show'''
Genre	Animation Comedy Variety
Created by	Fred Seibert
Developed by	Fred Seibert Larry Hueber
Theme music composer	Gary Lionelli
Opening theme	"What-a-Cartoon!"
Ending theme	"What-a-Cartoon!"
Country of origin	United States
No. of episodes	48 shorts
Running time	21-23 minutes
Production company(s)	Hanna-Barbera Studios (1995-1996) Cartoon Network Studios (1997-present)

What a Cartoon!' (promotionally known as World Premiere Toons, later known as The What a Cartoon! Show and then, The Cartoon Cartoon Show), was an American animation showcase project created by Fred Seibert for Hanna-Barbera Cartoons to be run on Cartoon Network. The project consisted of 48 short cartoons, intended to return creative power to animators and artists, by recreating the atmospheres that spawned the great cartoon characters of the mid-20th century. Each of 48 short cartoons mirrored the structure of a theatrical cartoon, with each film being based on an original storyboard drawn and written by its artist or creator.

The shorts from the project first aired on February 20, 1995 and promoted as World Premiere Toons. During the original run of the shorts the series was retitled as The What a Cartoon! Show until the final short aired May 23, 2008. The project served as the launching point for multiple successful Cartoon Network series, including Dexter's Laboratory, Johnny Bravo, Cow and Chicken, I Am Weasel, The Powerpuff Girls, Mike, Lu & Og, Courage the Cowardly Dog, Grim & Evil, The Grim Adventures of Billy & Mandy, Codename: Kids Next Door, and Whatever Happened to... Robot Jones?  as well as Fox TV's Family Guy. The series is influential for birthing a slew of original Cartoon Network hits and helping to revive television animation in the 1990s.