One and Done – People Who Have Only One Credited Movie Appearance
(for this one, TV movies DO NOT count)
- Klinton Spilsbury – The Legend of the Lone Ranger (1981)
- Peter Ostrum - Willy Wonka & the Chocolate Factory (1971)
- Dennis Wilson - Two-Lane Blacktop (1971)
Plenty of soundtrack credits and music video appearances, but his only credited movie role was that of the Mechanic, in Two-Lane Blacktop.