Ontario Liberal Party

The Ontario Liberal Party (OLP; French: Parti libéral de l'Ontario, PLO) is a political party in the province of Ontario, Canada. It has been one of the two main contenders for government for much of Ontario's history along with their conservative rival (currently the Progressive Conservative Party). Liberal ministries governed the province 63 of the approximately 160 years since Confederation, producing 10 of its 26 premiers.

The party has strong informal ties to the Liberal Party of Canada, but the two parties are organizationally independent and have separate, though overlapping, memberships. The provincial party and the Ontario wing of the federal party were organizationally one entity until members voted to split in 1976.

The party espouses the principles of liberalism, with their rival the Progressive Conservative (PC) Party positioned to the right and the New Democratic Party (NDP), which at times aligned itself with the Liberals during minority governments, positioned to their left.

The Liberals suffered its worst electoral defeat in the 2018 Ontario provincial election both in terms of seat count (seven) and popular vote (19.6%), losing official party status at the Legislative Assembly of Ontario. It was also the worst defeat of a governing party in Ontario history. Prior to the 2018 election, the party had won four consecutive elections since the turn of the century and had governed the province for the previous 15 years. In the 2022 provincial election, the Liberals saw a modest increase in support, finishing second in popular vote, but only winning eight seats.

In the most recent election in 2025, the party led by Bonnie Crombie won 14 seats and regained official party status. However, Crombie did not win her own seat and the Liberals remained the third-party in the legislature, despite having won a substantially larger share of the popular vote than the official opposition NDP (30% vs NDP's 18.6%).