Muhammad Ali's Greatest Fight is a 2013 American television drama film about the late boxer Muhammad Ali's refusal to report for induction into the United States military during the Vietnam War, focusing on how the United States Supreme Court decided to rule in Ali's favor in the 1971 case of Clay v. United States. The film was directed by Stephen Frears, from a screenplay written by Shawn Slovo based on the 2000 book Muhammad Ali's Greatest Fight: Cassius Clay vs. the United States of America by Howard Bingham and Max Wallace. It premiered on HBO on October 5, 2013.