33rd Parliament of Ontario
Minority parliament
Parliament leaders
Premier	Frank Miller
	David Peterson
Leader of the Opposition	David Peterson
	Frank Miller
	Larry Grossman
Party caucuses
Government	Progressive Conservative Party*
	Liberal Party * The Progressive Conservative Party briefly formed government but was defeated in a confidence vote.
Opposition	Liberal Party
	Progressive Conservative Party
Recognized	New Democratic Party*
* Providing confidence and supply for Liberal government.
Members	125 MPP seats
Sovereign
Monarch	Elizabeth II 6 February 1952 – present
Lieutenant Governor	John Black Aird
	Lincoln Alexander
← 32nd → 34th

The 33rd Legislative Assembly of Ontario was held from June 4, 1985, until July 31, 1987, just prior to the 1987 general election.

Hugh Alden Edighoffer served as speaker for the assembly.^[1]

Twenty-two days into the 33rd Parliament, Premier Frank Miller resigned following the defeat of his Progressive Conservative government in a motion of no confidence. Upon Miller's resignation, Lieutenant Governor John Black Aird appointed David Peterson, then Leader of the Opposition and Leader of the Ontario Liberal Party, as Premier. Peterson went on to form a minority government with the support of the Ontario New Democratic Party.