Thespis of Icaria (6th century BC) is claimed to be the first person ever to appear on stage as an actor in a play. In 534 B.C., mostly likely on what would have been November 23rd, Thespis took the stage at the Theatre Dionysus during a choral song and dance, and became the first man to take on the role of a character in a story. Prior to this performance, stories were told in third person narrative only, and no one had ever assumed the resemblance of another person for the purpose of storytelling. By becoming the first actor, Thespis not only created a new art form in acting, but had a substantial hand in changing the way stories were told and inventing theatre as we know it today.

In reverence to Thespis, actors throughout western history have been referred to as thespians.

In theatrical myth (or superstition), Thespis is said to exist now as a mischievous spirit, and when things go wrong in performances it is often blamed on his ghostly intervention. Like many superstitions, this belief ranges in different cases from being considered a humorous legend to being taken very seriously, with various charms and rituals being employed to either invite his approval or defend against him.

In theatre and acting craft, there is a minor school of thought known as "anti-thespian," which posits that it is inappropriate or artistically flawed to assume a character other than yourself. It is not a moral objection, but more a suggestion that actors should not make any effort to disguise or distract from who they are (in theory, because stories themselves are what matter, not the distraction of creating false depictions of people.)

See also:

• Aeschylus
• Sophocles
• Euripides
• Aristophanes
• Aristotle
• Dionysia