| Billy Down | |
| Fullname: | William Down |
| Birth Date: | 22 January 1898 |
| Birth Place: | Ryhope, Sunderland, England |
| Death Date: | April quarter 1977 (aged 77)[1] |
| Death Place: | Ashington, Northumberland, England |
| Height: | [2] |
| Position: | Goalkeeper |
| Years1: | 1920–1925 |
| Caps1: | 96 |
| Goals1: | 0 |
| Years2: | 1925–1927 |
| Caps2: | 50 |
| Goals2: | 0 |
| Years3: | 1927–1930 |
| Caps3: | 80 |
| Goals3: | 0 |
| Years4: | 1930 |
| Caps4: | 0 |
| Goals4: | 0 |
| Years5: | 1930 |
| Caps5: | 2 |
| Goals5: | 0 |
William Down (22 January 1898 – 1977) was an English professional association footballer who played as a goalkeeper. He played over 200 matches in the Football League for four clubs during the 1920s.