| William B. Seaman | |
| Birth Date: | c. 1875 |
| Death Place: | Washington, Pennsylvania, U.S. |
| Player Sport1: | Football |
| Player Years2: | 1895–1896 |
| Player Team2: | Washington & Jefferson |
| Player Positions: | Guard |
| Coach Sport1: | Football |
| Coach Years2: | 1897 |
| Coach Team2: | Waynesburg |
| Coach Years3: | 1900 |
| Coach Team3: | Washington & Jefferson (assistant) |
| Coach Years4: | 1902–1904 |
| Coach Team4: | Washington & Jefferson |
| Coach Years5: | 1906–1909 |
| Coach Team5: | Western Reserve |
| Coach Sport6: | Baseball |
| Coach Years7: | 1906–1907 |
| Coach Team7: | Washington Senators[1] |
| Overall Record: | 46–17–5 (football) 102–101 (baseball) |
| Championships: | 2 OAC (1907–1908) |
William Bryson "Budget" Seaman (c. 1875 – April 18, 1910)[2] was an American football and baseball player and coach. He served as the head football coach at Waynesburg College by—now known as Waynesburg University–in 1897, Washington & Jefferson College from 1900 to 1904, and Western Reserve University—now known as Case Western Reserve University—from 1906 to 1909. His Western Reserve team won two Ohio Athletic Conference titles, in 1907 and 1908, during his four-year tenure.[3]
Seaman played college football as a guard at Washington & Jefferson in 1895 and 1896. He began his coaching career in 1897 at Waynesburg.[4]
As a baseball manager of the Washington Senators in the Pennsylvania–Ohio–Maryland League for its only two seasons, he posted records of 57–44 in 1906—enough for league runner-up—and 45–75 in 1907.
Seaman was to remain the Western Reserve football coach for the 1910 season. However, he caught pneumonia in April 1910 and died in his hometown of Washington, Pennsylvania.[5]