The 42nd Ontario general election is scheduled to be held on or before June 7, 2018. Under amendments passed by the Legislative Assembly of Ontario in 2004, Ontario elections had previously been held on the first Thursday of October in the fourth calendar year unless the Assembly is dissolved earlier by the Lieutenant Governor of Ontario due to a motion of no confidence or on the advice of the Premier of Ontario. A motion of no confidence is unlikely as the current government has a majority, though Premier Kathleen Wynne stated in June 2015 that she would likely advise to dissolve the Legislature in the spring of 2018 rather than in October of that year in order to avoid any conflict with municipal elections and take advantage of better weather and longer days. Attorney General of Ontario Yasir Naqvi introduced Bill 45, the Election Statute Law Amendment Act, 2016, to the Legislative Assembly in October 2016 to amend the previous fixed election date law, which included moving the election date to the first Thursday in June of the fourth calendar year. The bill received royal assent on December 8, 2016.
On June 4, 2015, the government introduced Bill 115, Electoral Boundaries Act, 2015, to the Legislature, and it received Royal Assent on December 3, 2015. Bill 115 increases the number of electoral districts from 107 to 122, following along the boundaries set out by the federal 2013 Representation Order for Ontario, while preserving the special boundaries of the 11 seats in Northern Ontario set out in the 1996 redistribution.
June 12: The Liberal Party under Kathleen Wynne wins a majority government in the 41st Ontario general election. Progressive Conservative leader Tim Hudak announces his intention to step down following the selection of his successor.
July 2: Tim Hudak resigns as leader of the Progressive Conservatives. Simcoe—Grey MPP Jim Wilson is named interim leader.
July 24: The Liberals pass their May 1 budget in its final reading.
November 20: Joe Cimino, the New Democratic Party MPP for Sudbury, resigns his seat, citing family reasons.
February 5: Liberal candidate Glenn Thibeault is elected in a Sudbury by-election, gaining a seat that had been held by the NDP.
May 9: Patrick Brown, the Conservative federal MP for Barrie, is elected leader of the Progressive Conservative Party.
August 1: PC Simcoe North MPP Garfield Dunlop, resigns his seat to allow PC leader Patrick Brown to have a chance to run for a seat. Premier Kathleen Wynne orders a by-election for September 3, 2015.
August 28: PC Whitby—Oshawa MPP Christine Elliott resigns her seat.
September 3: PC Leader Patrick Brown is elected in the Simcoe North by-election.
September 24: Ontario Provincial Police lay charges in relation to the Sudbury byelection scandal.
December 3: Bill 115, the Electoral Boundaries Act, 2015, which increases the number of electoral districts from 107 to 122, receives Royal Assent.
February 11: Lorne Coe is elected in the Whitby—Oshawa by-election, maintaining the seat for the PC's.
March 22: Liberal Scarborough—Rouge River MPP Bas Balkissoon resigns his seat.
June 30: Liberal Ottawa—Vanier MPP Madeleine Meilleur resigns her seat.
September 1: PC candidate Raymond Cho is elected in the Scarborough—Rouge River by-election, gaining a seat held by the Liberals.
September 16: PC Niagara West—Glanbrook MPP and former PC leader Tim Hudak resigns his seat.
October 19: Two provincial by-elections are called for November 17 to fill vacant seats in the Ottawa—Vanier and Niagara—West Glanbrook ridings.
October 19: Attorney General of Ontario Yasir Naqvi introduces Bill 45, the Election Statute Law Amendment Act, 2016, which would move Ontario's fixed election date from the first Thursday in October to the first Thursday in June among other changes for First Reading.
November 1: Ontario Provincial Police announce charges under the provincial act against Gerry Lougheed and Patricia Sorbara (CEO and director of the 2018 Liberal campaign) for alleged bribery during a 2015 byelection. Sorbara announced that she will step down from the campaign.
November 17: PC candidate Sam Oosterhoff is elected in the Niagara West—Glanbrook by-election, and Liberal candidate Nathalie Des Rosiers is elected in the Ottawa—Vanier by-election.
December 8: The Election Statute Law Amendment Act, 2016 receives royal assent, moving Ontario's fixed election date to the first Thursday in June.
December 31: Liberal Sault Ste. Marie MPP David Orazietti resigns his seat.
Liberals
Glen Murray, Toronto Centre
New Democratic Party
Cheri DiNovo, Parkdale—High Park
Candidates by region
† = Not seeking re-election
‡ = Running for re-election in different riding
Italicization indicates candidate for nomination or declared interest
Highlight indicates nomination meeting has been scheduled
Strikethrough indicates nomination candidate disqualified or withdrew
