
For more information on provincial politics, see Politics in Ontario.
| Premier | Party | Term |
| Doug Ford | Progressive Conservative | 2018–present |
| Kathleen Wynne | Liberal |
2013–18
|
| Dalton McGuinty | Liberal | 2003–13 |
| Ernie Eves | Progressive Conservative | 2002–03 |
| Mike Harris | Progressive Conservative | 1995–2002 |
| Bob Rae | NDP | 1990–95 |
| David Peterson | Liberal | 1985–90 |
| Frank Miller | Progressive Conservative | 1985 |
| Bill Davis | Conservative | 1971–85 |
| John Robarts | Progressive Conservative | 1961–71 |
| Leslie Frost | Progressive Conservative | 1949–61 |
| Thomas Laird Kennedy | Progressive Conservative | 1948–49 |
| George A. Drew | Progressive Conservative | 1943–48 |
| Harry Nixon | Liberal | 1943 |
| Gordon Daniel Conant | Liberal | 1942–43 |
| Mitchell Hepburn | Liberal | 1934–42 |
| George Stewart Henry | Conservative | 1930–34 |
| Howard Ferguson | Conservative | 1923–30 |
| Ernest Drury | United Farmers of Ontario | 1919–23 |
| William Hearst | Conservative | 1914–19 |
| James Whitney | Conservative | 1905–14 |
| George William Ross | Liberal | 1899–1905 |
| Arthur Sturgis Hardy | Liberal | 1896–99 |
| Oliver Mowat | Liberal | 1872–96 |
| Edward Blake | Liberal | 1871–72 |
| John Sandfield Macdonald | Liberal-Conservative | 1867–71 |