The Unknown Known is a 2013 American documentary film about the political career of former U.S. Secretary of Defense and congressman Donald Rumsfeld, directed by Academy Award winning documentarian and filmmaker Errol Morris. It is a summary of 33 hours of interviews that Morris conducted with Rumsfeld over eleven separate sessions during visits to Newton, Massachusetts. The film was released on April 4, 2014 by Radius-TWC and is dedicated to the memory of Roger Ebert.