Dexter's Laboratory is an American animated television series created by Genndy Tartakovsky for Cartoon Network and the first original series for the channel under the Cartoon Cartoons moniker. The series follows Dexter, an enthusiastic boy-genius with a hidden science laboratory in his room, which he keeps secret from his unsuspecting parents. Dexter is at constant odds with his older and more extraverted sister Dee Dee, who regularly accesses the laboratory and inadvertently foils his experiments. Mandark, a nefarious boy-genius classmate who lives next-door to Dexter, attempts to undermine him at every opportunity. Prominently featured in the first and second seasons are other segments focusing on superhero-based characters Monkey, Dexter's pet lab-monkey with a superhero alter ego, and the Justice Friends, a trio of superheroes who share an apartment.

Tartakovsky pitched the series to Fred Seibert's animated shorts showcase What a Cartoon! at Hanna-Barbera, basing it on student films he produced at the California Institute of the Arts. Four pilots aired on Cartoon Network and TNT from 1995 to 1996. Viewer approval ratings led to a half-hour series, which consisted of two seasons totaling 52 episodes, airing from April 27, 1996, to June 15, 1998. On December 10, 1999, a television film titled Dexter's Laboratory: Ego Trip aired as the intended series finale, after which Tartakovsky focused his work on another series for Cartoon Network, Samurai Jack.

In November 2000, the series was renewed for two seasons, which began airing on November 18, 2001. Due to Tartakovsky's departure, Chris Savino served as showrunner, and a new team at Cartoon Network Studios produced the series. After 26 episodes, the fourth season concluded on November 20, 2003, ending the series.

Dexter's Laboratory, particularly its first two seasons, received critical acclaim and became one of Cartoon Network's most successful original series. It won three Annie Awards, with nominations for four Primetime Emmy Awards, four Golden Reel Awards, and nine other Annie Awards. Animators Craig McCracken, Seth MacFarlane, Butch Hartman, Paul Rudish, and Rob Renzetti worked on the series and later achieved further success in their careers in animation. Spin-off media include children's books, comic books, DVD and VHS releases, music albums, toys, and video games.