Ivan Gene LeBell (October 9, 1932 – August 9, 2022) is an American martial artist, stunt performer, actor, and former professional wrestler. Nicknamed "the Godfather of Grappling", LeBell is widely credited with popularizing grappling in professional fighting circles, serving as a precursor to modern mixed martial arts. LeBell has also worked on over 1,000 films and TV shows and has authored 12 books. In 2000, the United States Ju-Jitsu Federation (USJJF) promoted him to 9th Dan in jujitsu and taihojutsu. On August 7, 2004, the World Martial Arts Masters Association promoted LeBell to 10th Degree and in February 2005, he was promoted to 9th Dan in Traditional Judo by the USJJF. LeBell served as an inspiration for the character of Cliff Booth (Brad Pitt) in Quentin Tarantino's Once Upon a Time in Hollywood.