Ron Marchini (born March 4, 1945 in ) is an American karateka who according to many martial artists was one of the top then karate tournament fighters of all time.
Marchini is a member of the Black Belt Hall of Fame. In 1967, Marchini won the Pacific Coast Tournament. In 1969, Marchini was the number one ranked karate fighter in the United States. Marchini won Henry Cho's Tournament of Champions in 1968. According to Chuck Norris, Marchini was among the toughest opponents he ever faced. Marchini was considered to be the best defensive fighter in karate from 1967 to 1970. In 1972, Marchini was ranked the number 3 karate fighter in the United States.
Marchini was a soldier and drill sergeant in the U.S. Army. Marchini worked as a martial arts tournament fighter, school owner, actor, and producer. Marchini was the survivor of a drive-by shooting.
Marchini is the author of several books, including Power Training in Kung-Fu and Karate, The Ultimate Art: Renbukai Volume 1, The Ultimate Art: Renbukai Volume 2, The Ultimate Art: Renbukai Volume 3, and The Ultimate Art: Renbukai Volume 4. Marchini starred in the 1990 movie Omega Cop and its 1991 sequel Karate Cop as well as the movie Death Machines.