| William Shadoan | |
| Birth Date: | 8 December 1894 |
| Birth Place: | Somerset, Kentucky |
| Death Place: | Cape Girardeau, Missouri |
| Player Sport1: | Football |
| Player Years2: | 1921 |
| Player Team2: | Centre |
| Player Positions: | Guard |
| Coach Sport1: | Football |
| Coach Years2: | 1923–1924 |
| Coach Team2: | Valparaiso |
| Coach Sport3: | Basketball |
| Coach Years4: | 1923–1925 |
| Coach Team4: | Valparaiso |
| Overall Record: | 9–5–3 (football) 33–9 (basketball) |
William Parker Shadoan (December 8, 1894 – June 20, 1974) was an American football, basketball, and baseball coach and military officer. He served as head football, basketball, and baseball coach at Valparaiso University during the 1923–24 and 1924–25 academic years. Shadoan attended Centre College in Danville, Kentucky, where he played college football as a guard on the 1921 Centre Praying Colonels football team. He served in the United States Army during the Pancho Villa Expedition and with the American Expeditionary Forces in France during World War I. He reached the rank of colonel and later served as the superintendent of a number of military schools.[1]