#10. O.J. Simpson
He may have put on the performance of a lifetime in court (the first time), but he when he took a stab at playing security guard Harry Jernigan in The Towering Inferno (1974) he was horrendous. Except, of course, when the former football running back had to sprint from the fire. (Photo: WENN)

#9. Joe Namath
The star quarterback of the New York Jets tried to turn his on-field charisma into big-screen success. The famed playboy was a member of the bad boy bikers The Heads in C.C. and Company (1970), but critics agreed that, in the movies at least, Broadway Joe failed to score. (Photo: Getty Images)

#8. Wilt Chamberlain
The basketball legend had the size (7’1″) but not the acting chops to play bodyguard Bombaata in the 1984 flick Conan the Destroyer, the second film to star body builder ArnoldSchwarzenegger as the sword-swinging hero. Wilt the Stilt looked awfully small when it came to acting talent. (Photo: Getty Images)

#7. Muhammad Ali
Everyone loves the Champ, but he shouldn’t have been playing himself in The Greatest (1977). Will Smith did a much better job as Ali in Ali a quarter-century later. (Photo: Splash News)

#6. Bob Mathias
One of the greatest athletes ever, he won the Gold in the decathlon in the 1948 and 1952 Olympics. Naturally, producers wanted the handsome, 6’3″ medalist for films. Unfortunately, he chose the Italian sword-and-sandal epic The Minotaur (1960). Unfortunately, no one believed he couldn’t hit the fake-looking monster with a javelin! (Photo: Getty Images)

#5. Billie Jean King
The tennis great dominated her opponents on the court but was way out of her league in another court. She played a judge on Law and Order in the 2007 episode Fallout . The acting? Waaaay uncomfortable to watch. (Photo: WENN)

#4. Arnold Palmer
One of the greatest golfers in the world, right? Arnie played himself in the Bob Hope flick Call me Bwana (1963). Let’s just say he was as good an actor as his costar Bob Hope was a golfer. (Photo: Getty Images)

#3. Michael Jordan
Some say he’s the greatest athlete ever. But Bugs Bunny and company acted the
superstar off the screen in Space Jam (1996). Even Larry Bird and Charles Barkley were better…and they weren’t very good (in the film)! (Photo: Getty Images)

#2. Roman Gabriel
The tall, good-looking quarterback for the then-Los Angeles Rams, was another athlete who seemed to be destined for off-the-field stardom. Just one problem: he couldn’t act, as his stiff performance as a Cherokee Indian in John Wayne’s The Undefeated (1969) proved. (Photo: Getty Images)