John Fain is the main villain of the 1971 action/adventure movie Big Jake.

He was played by the late Richard Boone.

Fain led a vicious gang of kidnappers and criminals, who kill lots of the McCandle's family and friends and kidnaps Jacob's grandson for a 1,000,000.00 in a big red strongbox. Martha decides to summon her former husband, Jacob McCandles, gunfighter and main hero, to bring the box of money to the kidnappers, who plan to kill the boy get the money or not get the money. As Jacob and the heroes travel to meet the kidnappers, Fain meets Jacob and tells him that he's not a fool and is aware of all his bag of tricks like the other heroes hiding and watching Fain armed with guns and that if the heroes lose the money they will kill the boy. The heroes go to Mexico and meet with Fain and his gang at their hideout.

Fain and his gang warn Jacob and the rest of the heroes that if they try anything they'll destroy the boy and have a gun aimed at the boy. Fain brings out the boy, who Jacob meets for the first time, and Fain and his gang discover that the box of money is no more than a box of clipped bundles of newspaper and Jacob and the heroes plan to kill Fain and his gang. Jacob and the heroes kill all of Fain's gang and Fain rides up and is about to kill Jacob and his grandson but Fain is shot and killed by Michael McCandles, one of Jacob's sons and hero.