| William Armstrong | |
| Fullname: | William A. Armstrong |
| Club1: | Wakefield Trinity |
| Year1start: | 1920 |
| Year1end: | 22/23 |
| Appearances1: | 62 |
| Tries1: | 1 |
| Goals1: | 0 |
| Fieldgoals1: | 0 |
| Points1: | 3 |
| New: | yes |
| Retired: | yes |
William A. Armstrong was a professional rugby league footballer who played in the 1920s. He played at club level for Wakefield Trinity, as a or .
William Armstrong played in Wakefield Trinity's 3-29 defeat by Australia in the 1921–22 Kangaroo tour of Great Britain match at Belle Vue, Wakefield on Saturday 22 October 1921.[1]