| William Duncan McLeod | |
| Office1: | Ontario MPP |
| Term Start1: | 1902 |
| Term End1: | 1904 |
| Predecessor1: | Donald Robert McDonald |
| Successor1: | John Angus McMillan |
| Constituency1: | Glengarry |
| Party: | Conservative |
| Birth Date: | 4 April 1852 |
| Birth Place: | Kirk Hill, Glengarry County, Canada West |
| Death Place: | Glengarry County, Ontario |
| Occupation: | Farmer |
William Duncan McLeod (April 4, 1852 - August 14, 1908) was a cheese maker, farmer and politician in Ontario. He represented Glengarry from 1902 to 1904 in the Legislative Assembly of Ontario as a Conservative.
The son of Kenneth McLeod and Ann Duncan, he was born in Kirk Hill, Glengarry County, Canada West. In 1875, he married Jane McDougall. McLeod dealt in cheese and owned several factories. He was defeated by John Angus McMillan when he ran for reelection in 1904. He died four years later.[1]