| Playing career | |
|---|---|
| 1907–1909 | Kansas |
| Position(s) | Tackle, end |
| Coaching career (HC unless noted) | |
| 1910 | Haskell |
| 1911 | Muskingum |
| Head coaching record | |
| Overall | 2–13 |
William Caldwell was an American football player and coach. He served as the head football coach at Haskell Institute—now known as Haskell Indian Nations University—in Lawrence, Kansas for one season, in 1910, and Muskingum College—now known as Muskingum University in New Concord, Ohio for one season, in 1911, compiling a career college football coaching record of 2–13. Caldwell played college football for three seasons, from 1907 to 1909, at the University of Kansas.