| Number: | 61, 76, 66 |
| Position: | Defensive tackle |
| Birth Date: | January 3, 1949 |
| Birth Place: | Oakland, California, U.S. |
| Height Ft: | 6 |
| Height In: | 4 |
| Weight Lbs: | 250 |
| High School: | Oakland (CA) Skyline |
| College: | Utah State |
| Draftyear: | 1971 |
| Draftround: | 14 |
| Draftpick: | 361 |
| Pastteams: | |
| Statlabel1: | Sacks |
| Statvalue1: | 12.0 |
| Statlabel2: | Fumble recoveries |
| Statvalue2: | 4 |
| Statlabel3: | Defensive TDs |
| Statvalue3: | 1 |
| Pfr: | DunsBi20 |
William Elwyn Dunstan (born January 3, 1949) is a former American football defensive lineman in the National Football League (NFL) for the San Francisco 49ers, New York Jets, Philadelphia Eagles, Buffalo Bills, and the Los Angeles Rams. He played college football at Utah State University.
He is the son of former NFL offensive tackle Elwyn Dunstan.[1]