According to the book "Weird NJ" (Sceurman, Mark and Mark Moran, Barnes and Noble Books, 2004 ISBN 0-7607-3979-X) he was a descendant of the Morris County Van Cleefs who were infamous in the area for their strange living and "procreational" efforts. In fact, one trait that Lee had was that he had one green eye and one blue eye. According to the book, "this telltale characteristic was corrected in the movies with colored contact lenses".
During one summer in the early 1950s he was a camp counselor in NYC for Marc Furstenberg.
He had almost given up his acting career in the mid-'60s and turned to painting when he was cast by Sergio Leone in For a Few Dollars More (1965). It made him a superstar in Europe and restarted his career in the US, making him again a recognizable and bankable name.
He had three children from his first marriage: Deborah, Alan and David.
He was involved in a car accident in 1959 in which he lost his left kneecap. Doctors told him he would never be able to ride a horse again because of the injury. Within six months he was back in the saddle.
He was missing the last joint of his middle finger, a disfigurement prominently featured in the climactic gunfight of The Good, the Bad and the Ugly (1966). He actually lost it while building a playhouse for his daughter, although there were rumors that it happened in a road accident or a bar fight.
Interviewed in "Bad at the Bijou" by William R. Horner (McFarland, 1982).
One episode of his short-lived TV series, "The Master" (1984), was titled "The Good, The Bad and the Priceless".
Producer Stuart Cohen recently revealed that Van Cleef was considered for the role of Garry in John Carpenter's The Thing (1982), since Carpenter had recently worked with him on Escape from New York (1981).
Son of Clarence Leroy Van Cleef and wife Maria Lavinia Van Fleet, both mostly of Dutch ancestry.
Was on the short list of actors under consideration for arms dealer Brad Whitaker in The Living Daylights (1987).
Was portrayed as a bounty hunter in the Lucky Luke comic book "The Bounty Hunter".
Was the inspiration for the character Revolver Ocelot in the "Metal Gear" series of games.