The Oregon Shakespeare Festival (OSF) is a regional repertory theatre in Ashland, Oregon, United States, founded in 1935 by Angus L. Bowmer. The Festival now offers matinee and evening performances of a wide range of classic and contemporary plays not limited to Shakespeare. During the Festival, between five and eleven plays are offered in daily rotation six days a week in its three theatres. It welcomed its millionth visitor in 1971, its 10-millionth in 2001, and its 20-millionth visitor in 2015.

A repertory theatre, also called repertory, rep, true rep or stock, which are also called producing theatres, is a theatre in which a resident company presents works from a specified repertoire, usually in alternation or rotation.