William Dow Duncan
| Date of birth | 11 June 1892 | ||
|---|---|---|---|
| Place of birth | Port Chalmers | ||
| Date of death | 14 December 1961 (aged 69) | ||
| Height | 1.76 m (5 ft 9 in) | ||
| Weight | 83 kg (183 lb) | ||
| Rugby union career | |||
| Playing career | |||
| Position | Hooker | ||
| National team(s) | |||
| Years | Club / team | Caps | (points) |
| 1920–1921 |  New Zealand |
11 | (3) |
William Dow Duncan (11 June 1892 – 14 December 1961) was a New Zealand rugby player. He played eleven games with the All Blacks.