Cornerstone Theater Company is a theater company based in the United States that specializes in community-based collaboration. According to the mission statement published on the company's website, "Cornerstone Theater Company is a multi-ethnic, ensemble-based theater company. We commission and produce new plays, both original works and contemporary adaptations of classics, which combine the artistry of professional and community collaborators. By making theater with and for people of many ages, cultures and levels of theatrical experience, Cornerstone builds bridges between and within diverse communities in our home city of Los Angeles and nationwide."