Flash animation or Flash cartoon is an animated film that is created with the Adobe Animate (formerly Flash Professional) platform or similar animation software and often distributed in the SWF file format. The term Flash animation refers to both the file format and the medium in which the animation is produced. Flash animation has enjoyed mainstream popularity since the mid-2000s, with many Flash-animated television series, television commercials, and award-winning online shorts being produced since then.

In the late 1990s, when bandwidth was still at 56 kbit/s for most Internet users, many Flash animation artists employed limited animation or cutout animation when creating projects intended for web distribution. This allowed artists to release shorts and interactive experiences well under 1 MB, which could stream both audio and high-end animation.

Flash is able to integrate bitmaps and other raster-based art, as well as video, though most Flash films are created using only vector-based drawings, which often result in a somewhat clean graphic appearance. Some hallmarks of poorly produced Flash animation are jerky natural movements (seen in walk-cycles and gestures), auto-tweened character movements, lip-sync without interpolation, and abrupt changes from front to profile view.

Flash animations are typically distributed by way of the World Wide Web, in which case they are often referred to as Internet cartoons, online cartoons, or web cartoons. Web Flash animations may be interactive and are often created in a series. An  Flash animation is distinguished from a Webcomic, which is a comic strip distributed via the Web, rather than an animated cartoon.