Fringe theatre in the context of Edmonton Fringe Festival

A one-act play is a play that has only one act, as distinct from plays that occur over several acts. One-act plays may consist of one or more scenes. The 20-40 minute play has emerged as a popular subgenre of the one-act play, especially in writing competitions. One act plays make up the overwhelming majority of fringe theatre shows including at the Edinburgh Festival Fringe.

The origin of the one-act play may be traced to the very beginning of recorded Western drama: in ancient Greece, Cyclops, a satyr play by Euripides, is an early example. The satyr play was a farcical short work that came after a trilogy of multi-act serious drama plays. A few notable examples of one act plays emerged before the 19th century including various versions of the Everyman play and works by Moliere and Calderon. One act plays became more common in the 19th century and are now a standard part of repertory theatre and fringe festivals.

Theatre festivals are amongst the earliest types of festival. Classical Greek theatre was associated with religious festivals dedicated to Dionysus, called the City Dionysia. The medieval mystery plays were presented at the major Christian feasts. Theatre as an everyday part of life is a comparatively recent phenomenon.

In recent years, theatre festivals have been established to promote various types of theatre, such as the works of William Shakespeare and George Bernard Shaw. Many festivals, such as those in the fringe theatre movement, promote the work of beginning playwrights (called "new writing") and performers.