The Ontario Liberal Party held a leadership election in 1943 to choose a permanent replacement to Mitchell Hepburn who had been forced to resign at the end of 1942. Because the Ontario Liberal Party was in power, the winner of the race would also become premier of the province. Initially, Hepburn attempted to anoint Gordon Daniel Conant as his permanent successor but the caucus did not accept this and forced a full leadership convention which was won on the first ballot by former Provincial Secretary Harry Nixon. As Conant was ailing and had been hospitalized, Thomas McQuesten was Acting Premier on the day of the leadership convention.

Candidates

Premier Gordon Daniel Conant had also been a candidate but collapsed hours before the leadership vote and withdrew as a candidate.

Results

Results were as follows: There were 8 spoiled ballots. See Ontario Liberal leadership conventions