Toonami (a portmanteau of the words cartoon and tsunami suggesting a "tidal wave" of animated cartoons) is a brand of Cartoon Network, used initially for action-oriented programming blocks on Cartoon Network television channels worldwide, mostly showing American cartoons and Japanese anime, originating in the United States on March 17, 1997, and ended on September 20, 2008. It was revived on May 26, 2012 as a Saturday night anime block on Cartoon Network, reclaiming Adult Swim's Saturday anime block, similar to it's previous mature-geared "Midnight Run" incarnation which was that block's forerunner.

The Toonami brand name was subsequently used in the United Kingdom as the name of an action-oriented animation channel replacing a former Cartoon Network-owned channel, CNX, which had been a Toonami/live-action hybrid network. It has been hosted by two CGI hosts.

Toonami was Cartoon Network's primary action-animation block. The block, which made its world premiere on Monday, March 17, 1997, initially replaced Power Zone, Cartoon Network's most recent incarnation of the Super Adventures block which had been a staple on the network since October 1, 1992. Toonami was originally a weekday afternoon cartoon and anime block hosted by Space Ghost villain-turned-producer Moltar at the Ghost Planet Industries building from 1997 to July 9, 1999.