The Ontario Liberal Party is a political party in the province of Ontario, Canada. Founded in 1857, it is one of the major political parties in the region. The party traditionally supports progressive policies, including social justice, environmental protection, and economic development. The party's leadership has varied over the years, with notable figures such as Dalton McGuinty and Kathleen Wynne serving as premiers. The Ontario Liberal Party has faced challenges in recent elections, leading to a shift in its political influence within the Ontario Legislative Assembly.