9th Parliament of Ontario
The 9th Legislative Assembly of Ontario was in session from March 1, 1898, until April 19, 1902, just prior to the 1902 general election. The majority party was the Ontario Liberal Party led by Arthur Sturgis Hardy. George William Ross became the Liberal leader when Hardy retired in 1899.
François-Eugène-Alfred Évanturel served as speaker for the assembly.
Timeline
| Seat | Incumbent | Party | Vacated | Reason | By-election |
| Lennox | Bowen Ebenezer Aylsworth | October 20, 1898 | Election declared void | November 18, 1898 | |
| Huron West | James Thompson Garrow | November 2, 1898 | Resignation in exchange for withdrawal of election petition | December 8, 1898 | |
| Halton | John Roaf Barber | November 4, 1898 | Election declared void | December 8, 1898 | |
| Hastings North | William John Allen | November 13, 1898 | Resignation in exchange for withdrawal of election petition | December 27, 1898 | |
| Nipissing | John Loughrin | November 16, 1898 | Election declared void | December 27, 1898 | |
| Northumberland East | John Henry Douglas | November 18, 1898 | Election declared void | December 14, 1898 | |
| Elgin East | Charles Andrew Brower | April 1, 1899 | Election declared void | December 12, 1899 | |
| Peterborough West | James Robert Stratton | October 21, 1899 | Sought re-election upon appointment as Provincial Secretary and Registrar | November 7, 1899 | |
| Ontario South | John Dryden | November 21, 1899 | Election declared void | December 12, 1899 | |
| Waterloo North | Louis Jacob Breithaupt | October 19, 1900 | Election declared void | October 31, 1900 | |
| Huron West | James Thompson Garrow | March 12, 1901 | Election declared void | December 4, 1901 | |
| London | Francis Baxter Leys | April 15, 1901 | Sought re-election in support of removing a dam on the Thames River | July 9, 1901 |