William Smythe
William Smythe may refer to:
- W. E. Smythe, journalist, writer and founder of the Little Landers movement
- William Smythe , American physicist and mentor of six Nobel Prize laureates
- William James Smythe, general and colonel-commandant of the Royal Artillery
- William Smythe, Oxford college head
- Harry Smythe, pitcher in Major League Baseball
- William Smythe of the Smythe baronets
- William Smythe and namesake of Smythe Shoulder