| Date | September 17–19, 1964 |
|---|---|
| Convention | Royal York Hotel, Toronto, Ontario |
| Resigning leader | John Wintermeyer |
| Won by | Andy Thompson |
| Ballots | 6 |
| Candidates | 7 |
The Ontario Liberal Party leadership election, 1964, held on September 17–19, 1964 elected Andy Thompson as the leader of the Ontario Liberal Party. Thompson replace John Wintermeyer who resigned after losing his seat in the 1963 provincial election. Thompson won after six ballots against a field of seven other candidates.