It officially opened November 19, 2003, at Queen's Park in Toronto, and ended on June 5, 2007.

The membership was set by the 2003 Ontario general election on October 2, 2003, and it changed only somewhat due to resignations and by-elections.

It was controlled by a Liberal Party majority under Premier Dalton McGuinty.

The Official Opposition was the Progressive Conservative Party, led first by Ernie Eves, and later by John Tory.

Resigned seat August 19, 2005, in order to accept appointment as Canada's ambassador to the Dominican Republic.