Great Lakes Theater, originally known as the Great Lakes Shakespeare Festival, is a professional classic theater company in Cleveland, Ohio, United States. Founded in 1962, Great Lakes is the second-largest regional theater in Northeast Ohio. It specializes in large-cast classic plays with a strong foundation in the works of Shakespeare and features an educational outreach program. The company performs its main stage productions in rotating repertory at the Hanna Theatre in Playhouse Square, which reopened on September 20, 2008. The organization shares a resident company of artists with the Idaho Shakespeare Festival. On its main stage and through its education programs, GLT connects approximately 85,000 adults and students to the classics each season.

The Hanna Theatre is a theater at Playhouse Square in downtown Cleveland, Ohio, United States. It is one of the original five venues built in the district, opening on March 28, 1921. The Hanna Theatre reopened in 2008 as the new home of Great Lakes Theater Festival after a major renovation by the classic theater company.