| William Hargraft | |
| Office1: | Ontario MPP |
| Term Start1: | 1875 |
| Term End1: | 1879 |
| Predecessor1: | Charles Gifford |
| Successor1: | John Collard Field |
| Constituency1: | Northumberland West |
| Party: | Liberal |
| Birth Date: | 16 October 1829 |
| Birth Place: | Templemore, County Tipperary, Ireland |
| Death Place: | Northumberland County, Ontario |
| Occupation: | Businessman |
William Hargraft (October 16, 1829 - July 8, 1887) was an Ontario merchant and political figure. He represented Northumberland West in the Legislative Assembly of Ontario from 1875 to 1879 as a Liberal member.
He was born in Templemore, County Tipperary, Ireland in 1829, the son of the local postmaster, George Hargraft. He came to Cobourg, Upper Canada with his family in 1833. In 1853, he married Mary Ross. Hargraft served on the town council for Cobourg, also serving as mayor and a commissioner of the Cobourg Town Trust. He was a director of the Hand-in-Hand Fire Insurance Company.
His son John later served as a member of the House of Commons.