Ontario Liberal Party

The Ontario Liberal Party (OLP, in French the Parti libéral de l'Ontario) is a provincial political party in Ontario, Canada, and for much of the province's history one of the two main contenders for government alongside its conservative rival, currently the Progressive Conservative Party. Liberal ministries governed Ontario for 63 of the roughly 160 years since Confederation and produced 10 of its 26 premiers. The party descends from the Reform tradition of Robert Baldwin and William Lyon Mackenzie and was built by George Brown, who in 1857 joined the Reformers and the Clear Grits. It has strong informal ties to the Liberal Party of Canada, but the two have been organisationally independent since members voted to split in 1976. It suffered its worst defeat in 2018, losing official party status, and won 14 seats under Bonnie Crombie in 2025. It espouses the principles of liberalism.