Shortform improvisation (often referred to simply as shortform) is an approach to improvisational theatre and improvisational comedy consisting of a series of games or structures that each encompass a single scene, with no narrative relationship to prior or subsequent scenes.

In shortform, audiences are asked for suggestions, or inputs, that are incorporated into the structure that is about to be performed. These inputs are solicited before each structure during the course of an improv performance. Television audiences would be most familiar with shortform through the UK and US versions of the television show Whose Line Is It Anyway? Many of the structures familiar to Whose Line Is It Anyway? audiences have variations that can be seen performed by improvisational troupes around the world. Shortform improvisation is performed around the world and is closely identified with the competitive improv formats ComedySportz and Theatresports.

The shortform approach is contrasted with longform improvisation, or longform. The superiority or inferiority of one approach versus another is a continuing subject of discussion in the improv community.