Adult Swim (stylized as [adult swim] or [as]) is an American cable network that operates every night from 8:00 p.m. to 6:00 a.m., Eastern and Pacific Time, on Cartoon Network. Both networks are owned by Time Warner through the Turner Broadcasting System subsidiary. It is programmed by Williams Street Productions, a subsidiary of Turner, which also developed two prior television programming blocks seen on Cartoon Network: Toonami (which later became a block on Adult Swim in 2012) and Miguzi. The name comes from a phrase used by public swimming pools in the United States to label designated times when children are restricted from using the facilities in favor of adults.

Debuting as a programming block on Cartoon Network in 2001, Adult Swim was established as alternative programming during the late night hours when Cartoon Network's primary target audience, children between the ages of 7 to 15 would normally be sleeping. Much of Adult Swim's general content is known for its risqué, unorthodox and often bizarre presentation, while many of the series features are developed in stark contrast with traditional American television programs. The network was granted its own Nielsen ratings report from Cartoon Network due to targeting a separate demographic. The block features stylistically varied animated and live-action shows including original programming, syndicated series mainly consisting of Fox animated programming, short films, OVAs, and Japanese anime, generally with minimal or no editing for content.

In the United States, Adult Swim has frequently aired recent or older adult animation features, Japanese anime, mockumentaries, sketch comedy, live-action, and pilots. Shows may have sexual themes, frank sexual discussion, nudity, strong language, and graphic violence. While the network features comedies and dramas of all types, many of its programs are aesthetically experimental, transgressive, improvised, and surreal in nature. Adult Swim has contracted with various studios known for their productions in absurd and shock comedy.

In February 2015, Adult Swim was available to approximately 96,390,000 pay television households (82.8% of households with television) in the United States.