| William Henry Hammell | |
| Office1: | Ontario MPP |
| Term Start1: | 1883 |
| Term End1: | 1894 |
| Predecessor1: | Charles Robinson |
| Successor1: | Edward Alfred Little |
| Constituency1: | Cardwell |
| Party: | Conservative |
| Birth Date: | 22 December 1845 |
| Birth Place: | Tecumseth Township, Simcoe County, Canada West |
| Death Place: | Simcoe, Ontario |
| Occupation: | Farmer |
| Children: | 5 |
William Henry Hammell (December 22, 1845 - June 19, 1937) was an Ontario farmer and political figure. He represented Cardwell in the Legislative Assembly of Ontario from 1883 to 1894 as a Conservative member.
He was born in Tecumseth Township, Simcoe County, Canada West in 1845, the son of Irish immigrants and studied at the Rockwood Academy. He married Maggie Robinson in 1878. Hammell was reeve for Tecumseth and a director for the Simcoe Mutual Fire Insurance Company.