The Green Party of Ontario (GPO; , PVO) is a political party in Ontario, Canada. It has run candidates in every Ontario election since 1985, and has contested every riding in elections since 2007.
The party's support peaked in the 2007 election at 8% of the popular vote, but dropped in the following election in 2011. In the four general elections since, its vote share has hovered around the 5% level. In the 2025 election, Green Party candidates were elected in two ridings.
The party is led by Mike Schreiner, who has represented the riding of Guelph since he first won election there in 2018 and became his party's first member of the Legislative Assembly of Ontario. The party gained a second MPP when Aislinn Clancy won the 2023 Kitchener Centre byelection. She held on to the seat in the 2025 general election.
History
Early years, 19831990
In mid-1983, inspired by the electoral success of the Greens in West Germany, a small group of Ontarians launched a provincial Green Party. Starting with around 40 members and informally led by Dr. Trevor Hancock, the fledgling party began to develop a platform and sought to gather the 10,000 signatures necessary for obtaining official party status.
By the following year, their petition had been endorsed by 11,665 eligible voters, and on 4 July 1984, the Green Party of Ontario was approved by the Ontario Commission on Election Contributions and Expenses, bringing the number of registered parties in Ontario to eight. The party could accept contributions and issue tax receipts, and was the second green party to be registered in Canadathe Green Party of British Columbia having been registered the year before. (The Green Party of Canada was registered federally a month later).
With nine chapters and nearly 500 members, the Green Party of Ontario was described as being pro-peace, pro-environment, and cutting across the political left and right. Hancock was nominally leader, but the party platform rejected centralized power.
In 1985 the party contested its first election, fielding nine candidates who collected a combined 5,345 votes. This represented 2% of the 264,076 votes cast in those nine ridings. Christopher Kowalchuk received 2,008 out of 34,241 votes, almost 6%, in the riding of Oakville. But the other eight Green candidates each drew well under 1,000 votes.
Disappointed by these results, many of the original members lost interest and left the party, which became highly decentralized, with no leader, no policy development, and no support structure for candidates.
With seven candidates in the 1987 election, the party fared worse, collecting 3,398 votes. Again only one candidate received more than 1,000 votesChristopher Kowalchuk, this time running in Oakville Southand the other six candidates averaged less than 400 votes each.
In the 1990 election, the Greens had hopes of winning the Parry Sound riding, where their candidate Richard Thomas was running against Conservative incumbent Ernie Eves for the third time. Eves, a future premier, had first won the seat in 1981 when he beat Thomas, then running for the Liberals, by just six votes (earning Eves the ironic sobriquet, "Landslide Ernie"). Thomas, who placed third in the 1982 Ontario Liberal party leadership race, contested the riding for the Liberals again in 1985 and captured 44% of the vote but lost to Eves, who received 51%.
Running for the Greens in 1990, Thomas placed thirdahead of the NDPwith 4,061 votes. This was less than half the vote count he had scored as a Liberal, yet it set a record17 years would pass before an Ontario Green candidate would win more votes. Overall the Ontario Greens increased their presence and their support in the 1990 election, with 40 candidates garnering 30,097 votes.
19931999
By 1993, the Green Party of Ontario, with between 100 and 200 members, was transforming into a more structured political organization, and it had its first official leader: Ottawa school teacher Frank de Jong. Born in 1955 to Dutch immigrants, de Jong was raised on a dairy farm near Arthur. For several years he had been involved with the Green parties of both Ontario and Canada, and had been a candidate in several elections.
The following year, de Jong bicycled 2,000 km around the province on a pre-election tour, spreading the message that the Greens were not a one-issue party concerned only with the environment. The party platform promoted preventative health care, community-based education, economic development, and electoral reform.
The 1995 election catapulted the Progressive Conservatives from third party in the legislature to majority government. In their wake, all other parties suffered losses, and the Greens were no exception—their previous vote share was cut in half. The 37 Green party candidates collected 14,108 votes.
By 1999, party membership had reached about 400 and leader de Jong had moved to Toronto, where he taught public school. The party had an office but no paid staff and continued to lean to the left with its environmental aspirations (support wind and solar power, phase out nuclear plants, discourage automobiles, encourage rail). Yet the party platform also contained right-wing aspects (favour free markets and balanced budgets, oppose income tax). Other proposals included a four-day work-week, to reduce stress and unemployment, and support for stay-at-home parents.
The Greens were not expecting to elect any MPPs in the 1999 electionde Jong saw the campaign as an opportunity to bring forward environmental issues, and hoped to lay the groundwork for electing members within the next decade. The party ran 58 candidates and amassed 30,781 votes, regaining its earlier popularitythough the votes were spread across more ridings than before.
20012006
In 2001 the Greens enjoyed an exceptional result in a March by-election in Parry Sound—Muskoka. Richard Thomas ran again and placed third, capturing just over 12% of the vote—almost quadruple the NDP's share.
Ontario leader Frank de Jong was encouraged when the Green Party of British Columbia, taken seriously by the media for the first time, got 12% of the vote in the May 2001 electionhe felt that greens across Canada were gaining momentum.
By the time of the GPO annual general meeting later that year, the party had 900 members. More than 100 attended, making it the biggest turnout yet. Held in Port Hope on 3 November 2001, the all-day event included speeches, votes for party positions, and work on resolutions. Deputy leader Judy Greenwood-Speers of Waterloo had set in motion a leadership challengesomething that was allowed at any annual general meeting. Frank de Jong had last survived a challenge in 1999, and staved off this one with 271 votes to 167 for Greenwood-Speers.
By late 2002 the GPOwhose province-wide support had always been less than the margin of errorwas finally registering in public opinion polls, achieving 6% in an October 2002 Ipsos Reid poll. Subsequent polls showed support gradually decreasing over the next few months, and by the summer of 2003 the Greens were back in margin-of-error territory. But their membership had grown to almost 1,200.
In the October 2003 election, the party reaped 126,651 votes, a share of 2.82%. Two of their candidates placed third, ahead of the NDP: Tom Manley in Stormont—Dundas—Charlottenburgh, and Frank de Jong, running in Dufferin—Peel—Wellington—Grey, where he grew up on his family's dairy farm. Overall, the Greens contested 102 out of a possible 103 ridings and placed fourth in 92 of them.
Prior to the election, an Oracle poll found that 73% of Ontario voters thought the Green party should be included in the televised leaders' debate, but de Jong was excluded, and his appeal to the CRTC was rejected.
Between the 2003 and 2007 elections, the Green party consistently scored around 8% support in public opinion polls, though in nine out of ten by-elections in that period their vote share was lower. The exception was the March 2005 by-election held to replace former opposition leader Ernie Eves, who had resigned his Dufferin—Peel—Wellington—Grey seat. Running in that by-election against Progressive Conservative leader John Tory, Green leader Frank de Jong placed fourth but received almost 10% of the vote.
In late October 2005 de Jong narrowly passed a leadership review, requiring at least two-thirds support, at the party's annual general meeting. Attended by almost 200, it was held at Geneva Park north of Orillia. One of the resolutions passed called for lowering the voting age to sixteen years.
At the party's 2006 annual general meeting, constitutional changes were made, such as requiring gender-paritied representatives from each of six regions, gender-paritied deputy leaders, and the creation of multiple functionary roles separated from the provincial executive. One of the first acts of the new provincial executive was to strike a hiring committee to bring on a full-time campaign manager to ensure election readiness.
2007 Campaign
In the run-up to the October 2007 election, opinion polls showed the Greens' province-wide support climbing into double-digits for the first time. Membershipwhich four years earlier had been around 1,200was close to 3,000 and the party could now afford a paid staff member.
Despite the Greens polling just 2% below the NDP, de Jong was again excluded from the televised leaders' debate. According to the broadcasters, the Greens failed to qualify by not having seats in the legislature, by not running a full slate of candidates, and by having no chance of influencing the outcome of the election. Though the first point was true, the second was factually incorrect, and the third was arguably false.
The campaign platform proposed reducing personal taxes by cancelling the health tax and by shifting some of the burden away from homeowners and businesses to environmentally harmful activities, while remaining revenue neutral overall. The party supported the public health system and wanted an end to separate school funding. Generally, the party sought to encourage economic prosperity, environmental stewardship, and social justice, not by spending more money, but by shifting priorities to achieve sustainable results. The party was staking out the centre of the political spectrum: according to de Jong, right-versus-left was passénow it was green-versus-grey.
With its free-enterprise philosophy, the Green party had few links to the green establishment, i.e. the big NGO's, which tended to support the mainstream parties. Leader de Jong described his relationship with green organizations as tenuous.
The Green party fielded a full slate of 107 candidates in the 2007 election, and in at least half of the ridings, the Greens mounted robust campaigns. The bar to being a candidate was higher than before. Upbeat and full of enthusiasm, de Jong took his positive message across the province and attracted much more media attention than in the past
Many voters liked the Green party platform, with its combination of environmentalism and libertarian economics, and importantly, opposition to public funding for catholic schools and other faith-based educationa clear stand that was distinct from the other parties.
Election and aftermath
After the polls closed on October 10, 2007, the Green party's tally was 354,897 votes, or 8.02%. Though still shut out of the legislature, the party had almost tripled its 2003 vote share, finished third in 18 ridings, and finished second in Bruce—Grey—Owen Sound, where Shane Jolley received 15,039 votes, more than any green party candidate in Canadian history at that time.