It took two nights to film the sequence in which Squire Western chases after Tom. The second night, Hugh Griffith managed to undo the wiring on his riding crop, and actually hit Albert Finney with it, drawing blood. In character, Finney turned on Griffith and said, "I can't abide to be whipped, Squire," then punched him in the face. Each stalked off the set, swearing never to work with the other again.
This was the last film that President John F. Kennedy saw during a stopover in Palm Beach, Florida, en route to Dallas, Texas (November 17, 1963).
Welsh singer Tom Jones (born Thomas John Woodward) chose his professional stage name from the title character/protagonist of this film.
Hugh Griffith was reportedly drunk through much of the production; the scene in which his horse falls on him was not planned, and many believed he was saved by virtue of his inebriated condition. The film incorporated every frame of footage before rescuers entered the frame to save him.
Much of the scene in which Tom Jones and Mrs. Waters are eating together was improvised during the three hours it took to shoot, and the actors felt the effects from the food for days.