Castillo Theatre was created by a collective of political activists and artists and led for more than two decades by its artistic director Fred Newman. Its goal has always been to do more than produce plays; Castillo has sought to redefine the form and content of American political theater. On the occasion of its production of Martinican poet/playwright Aimé Césaire's play A Season in the Congo, Césaire wrote that Newman and Castillo’s work "is a new genre... it's not just artistic. It's philosophical — an attitude toward life, performed by people who transcend the differences of color, of race, and of language."

Castillo has become known for theater that’s topical, entertaining and avant-garde; for being the foremost American producer of the works of Heiner Müller; for presenting the Otto René Castillo Award for Political Theatre; and for being a multiracial home for Black theater. The Castillo Ensemble has worked with Newman for over a decade, most frequently performing in the 30 full-length plays and musicals he has written, and in the works of Müller he has often directed.

Newman and Castillo have left their imprint on many areas of cultural and social significance, including the nature of performance on and off the stage; issues of identity and truth; the nature of American democracy; the rise of fascism and failure of communism in Europe; and the legacy of American slavery and racism.

In all Castillo has produced 115 productions, working in many different genres: the avant-garde, the American musical, vaudeville, choreo-poems, historical dramas, hip-hop and improvisational comedy. Castillo has produced the work of major black theatre/performing artists as diverse as Laurence Holder, Ed Bullins, Ntozake Shange (with Woodie King, Jr.), and contemporary modern dancer/choreographer Desmond Richardson.

Privately funded from the beginning, Castillo’s bold move from far west SoHo to West 42nd Street and the $12.5 million All Stars Project performing arts and education center in 2003 established it as part of New York’s theater district, and has brought thousands of diverse audience members — young and old, sophisticates and first-timers — to Castillo.

In 2004, Castillo dramaturg Dan Friedman founded Youth Onstage!, a performance school and youth theater that’s free to all who participate, as a place where young artists create theater that expresses their views about the world.

Celebrating more than a quarter century of producing, development, political activism and philosophy continues to resonate in all of Castillo's productions.