| Birth Date: | 19 March 1991 |
| Birth Place: | Frankfurt, Germany |
| Height: | 6inchesft2inchesin (ftin) |
| Weight: | 260lb |
| Ru Amateuryears: | 2015 |
| Ru Amateurclubs: | Army |
| Ru Clubyears: | 2018 2019 |
| Ru Proclubs: | Seattle Seawolves San Diego Legion |
| Ru Clubcaps: | 8 4 |
| Ru Clubpoints: | (21) (2) |
| Ru Clubupdate: | 30 December 2020 |
| Repsevensyears1: | 2014–2016 |
| Repsevensteam1: | United States |
| Repsevenscomp1: | 7 |
| Ru Nationalyears: | 2012–2016 |
| Ru Nationalteam: | United States |
| Ru Nationalcaps: | 7 |
| Ru Nationalpoints: | (27) |
| Ru Ntupdate: | 30 December 2020[1] |
William Holder (born March 19, 1991) is an American rugby player who played for the San Diego Legion in Major League Rugby (MLR) and for the United States national rugby union team 15s and sevens side as a fly half.
Holder won a bronze medal at the 2015 Pan American Games.
He graduated from the United States Military Academy and serves as first lieutenant with the United States Army. He took up rugby in the third grade inspired by his father.