The Second Parliament of Ontario was in session from March 21, 1871, until December 23, 1874, just prior to the 1875 general election.
The 4th Parliament of Ontario was in session from June 5, 1879, until February 1, 1883, just prior to the 1883 general election. The majority party was the Liberal Party led by Oliver Mowat.
The 9th Legislative Assembly of Ontario was in session from March 1, 1898, until April 19, 1902, just prior to the 1902 general election. The majority party was the Ontario Liberal Party led by Arthur Sturgis Hardy. George William Ross became the Liberal leader when Hardy retired in 1899.
The 10th Legislative Assembly of Ontario was in session from May 29, 1902, until December 13, 1904, just prior to the 1905 general election. The majority party was the Ontario Liberal Party led by George William Ross.
The 12th Legislative Assembly of Ontario was in session from June 8, 1908, until November 13, 1911, just prior to the 1911 general election. The majority party was the Ontario Conservative Party led by Sir James P. Whitney.
The 13th Legislative Assembly of Ontario was in session from December 11, 1911, until May 29, 1914, just prior to the 1914 general election. The majority party was the Ontario Conservative Party led by Sir James P. Whitney.
The 14th Legislative Assembly of Ontario was in session from June 29, 1914, until September 23, 1919, just prior to the 1919 general election. The majority party was the Ontario Conservative Party led by Sir James P. Whitney.
The 18th Legislative Assembly of Ontario was in session from October 30, 1929, until May 16, 1934, just prior to the 1934 general election. The majority party was the Ontario Conservative Party led by George Howard Ferguson.
The 19th Legislative Assembly of Ontario was in session from June 19, 1934, until August 25, 1937, just prior to the 1937 general election. The Ontario Liberal Party led by Mitchell Hepburn came to power with a majority government.
The 20th Legislative Assembly of Ontario was in session from October 6, 1937, until June 30, 1943, just prior to the 1943 general election. The majority party was the Ontario Liberal Party led by Mitchell Hepburn.
The 21st Legislative Assembly of Ontario was convened following the 1943 Ontario general election and was in session from August 4, 1943, until March 24, 1945, just prior to the 1945 general election. The Ontario Progressive Conservative Party, formerly the Ontario Conservative Party, led by George Drew formed a minority government. The Liberals, having lost seats to both the Conservatives and the Co-operative Commonwealth Federation, fell to third place.
The 22nd Legislative Assembly of Ontario was in session from June 4, 1945, until April 27, 1948, just prior to the 1948 general election. The majority party was the Ontario Progressive Conservative Party led by George Drew.
The 25th Legislative Assembly of Ontario was in session from June 9, 1955, until May 4, 1959, just prior to the 1959 general election. The majority party was the Ontario Progressive Conservative Party led by Leslie Frost.
The 26th Legislative Assembly of Ontario was in session from June 11, 1959, until August 16, 1963, just prior to the 1963 general election. The majority party was the Ontario Progressive Conservative Party led by Leslie Frost.
The 27th Legislative Assembly of Ontario was in session from September 25, 1963, until September 5, 1967, just prior to the 1967 general election. The majority party was the Ontario Progressive Conservative Party led by John Robarts.
The 28th Legislative Assembly of Ontario was in session from October 17, 1967, until September 13, 1971, just prior to the 1971 general election. The majority party was the Ontario Progressive Conservative Party led by John Robarts.
The 29th Legislative Assembly of Ontario was in session from October 21, 1971, until August 11, 1975, just prior to the 1975 general election. The majority party was the Ontario Progressive Conservative Party led by Bill Davis.
The 30th Legislative Assembly of Ontario was in session from September 18, 1975, until April 29, 1977, just prior to the 1977 general election. The Ontario Progressive Conservative Party led by Bill Davis formed a minority government.
The 31st Legislative Assembly of Ontario was in session from June 9, 1977, until February 2, 1981, just prior to the 1981 general election. The Ontario Progressive Conservative Party led by Bill Davis formed a second consecutive minority government.
The 37th Legislative Assembly of Ontario, Canada's most populous province, was in session from June 8, 1999, until May 5, 2003. Its membership was set by the general election of 1999. Majority was held by the Ontario Progressive Conservative Party led by Mike Harris.
