The 20 Seats To Watch in Ontario

April 25, 2025

Ontario is the most important and seat-rich province in the country. In just a couple of days, 122 seats will be up for grabs, and there will be a plethora of new ridings all across the province. I did a 20-seat list for the provincial election just a few weeks ago that you can read here. There’s a surprising amount of overlap between these two lists despite being in completely different political landscapes. It’s well known that who Ontarians vote for to go to Toronto versus those who vote to go to Ottawa are often on opposing benches. Since Trudeau’s election in 2015, every Ontario election since then has gone for Ford. While Pierre Trudeau was in power between 68 and 79 and then 80 and 84, every Ontario election in that period was one that elected Progressive Conservatives. Bill Davis even became the second longest serving Premier in Ontario history, serving for almost a decade and a half from 71 and 85, an interesting time frame between the two. It’s hard to geographically balance such a dominant province like this (over a third of seats are in this province alone) when the GTHA so centrally powers politics in Ontario, but there are some interesting races from Windsor to Wawa and Cumberland to Chapleau!

The List

1. Milton East-Halton Hills South

2. Markham-Unionville

3. Niagara Falls-Niagara-on-the-Lake

4. Toronto-St. Paul’s

5. Eglinton-Lawrence

6. York Centre

7. Taiaiako'n-Parkdale-High Park

8. Aurora-Oak Ridges-Richmond Hill

9. Sault Ste. Marie-Algoma

10. Kapuskasing-Timmins-Mushkegowuk

11. Kitchener Centre

12. Hamilton Centre

13. Hamilton Mountain

14. Peterborough

15. London-Fanshawe

16. Kingston and the Islands

17. Windsor West

18. Bay of Quinte

19. Prescott-Russell-Cumberland

20. Nepean

Milton East-Halton Hills South

Starting on the west side of the GTHA, Milton East-Halton Hills South is a new riding, split mainly from the former riding of Milton. This seat includes Georgetown, one of the most Conservative areas in the region, and Milton, one of the fastest-growing and most left trending areas in the region.

The new riding of Milton East-Halton Hills South, with the new riding outlined in yellow, Milton in the south and Georgetown in the north

There’s a significant minority population in the riding. If South Asians are swinging right, like some polls may indicate, this riding would appear to be one of the only Liberal notional losses from 2021.

Seats that would’ve gone Liberal in the 2021 Election, transposed on the new map and their current projected margins

Representing the Conservatives, currently up in the model, is Parm Gill, no stranger to this region’s politics. He was the MP for Brampton-Springdale from 2011-2015, then elected to the provincial legislature for the riding of Milton from 2018-2024, when he resigned to receive the nomination here and start his next federal campaign. He’s also not without his controversies, with a nasty campaign between him and Ruby Dhalla in 2008 in Springdale, before defeating her in the Liberal crash of 2011. There have also been several controversies of his, regarding the use of political leverage and ethics, campaign donations, sex-ed reform and family values, and, most recently, a local scandal regarding the use of a facility for a campaign event where early voting was taking place. He has a lot of baggage, which could hurt him in this race. This seat would’ve been close, had it existed, in 2019 and 2021, and this time is no different. Gill is going against Kristina Tesser Derksen, a locally successful Milton town councillor. In an election where the Liberals are soaring, this riding is solidly in first for ones to watch.

Markham-Unionville

Another riding in the GTHA, Markham-Unionville, is in York Region, a key area for anyone forming government in Canada. When the Conservatives were leading with humongous margins, almost all of York Region was projected to vote blue, but when Trudeau’s Liberals won in 2015, 3/10 ridings here voted Conservative. 2 are safe blue, York-Simcoe (newly minted as York-Durham and New Tecumseth-Gwillimbury) and Thornhill. Ironically, Markham-Unionville was that third seat with the exit of longtime Liberal MP John McCallum. Bob Saroya was elected in 2015 and 2019 before losing in 2021 to notable police officer Paul Chiang, which the Conservatives blamed Chinese election interference on the loss in this riding. Over half of residents in this riding reported that a Chinese language was their mother tongue in the 2021 Census, with only a quarter reporting English. Almost 90% of residents here reported being a visible minority, which, like in Milton, could play a massive role in how this riding plays out. Michael Ma is leading by 4 points, and he’s previously been involved in campaigns in Don Valley and Scarborough. The Liberals had internal troubles in candidacies here; incumbent MP Paul Chiang stepped down after stating that the previous Conservative candidate, Joe Tay, a Hong Kong activist, now running in Don Valley North, should be turned over for a bounty to Chinese officials. Peter Yuen replaced Chiang after he stepped down, Yuen is a retired police officer who has come under controversy for being directly linked to organizations connected with the Chinese Communist Party. If we get more information on racial voting polling, this riding will be one to watch in the model and on election night.

Niagara Falls-Niagara-on-the-Lake

Out of the GTHA this time, Niagara Falls-Niagara-on-the-Lake is a riding right on the border of the USA, the riding lost Fort Erie in the redistribution, which doesn’t help the Conservatives. This riding is the Liberal dream with the perfect mix of factors that are helping them here. The PCs provincially did badly and really underperformed in the Niagara area. The border and tariffs are a big issue nationwide, especially in far Southern Ontario, where manufacturing is important to people here. And if rural/urban polarization hits this region, then the Liberals would be on track to win here, not to mention that their candidate, Andrea Kaiser, is a longtime councillor in Niagara. She leads by 5 points over the incumbent, Tony Baldinelli, initially elected in 2019, replacing former notable MP Rob Nicholson. This seat hasn’t elected a Liberal in 25 years and hasn’t consistently voted for the party in another 25 years on top of that, and the PCs provincially actually went down in vote share. This riding could indicate how big of an impact tariffs have on the electorate, as polls show it’s one of the top issues and one that the Liberals have a big lead among.

Toronto-St. Paul’s

Switching to Toronto for the next few ridings on the list, Toronto-St. Paul’s flipped in a by-election in 2024 after the MP of almost 30 years, Carolyn Bennett, resigned during the peak of Conservative support. After the by-election took place, the model had the Conservatives projected to win 243 seats to the Liberals’ 42, the second worst projection for the Liberals this entire term.

Historical Results in Toronto-St. Paul's and St. Paul's

The general election happening now is a rematch from the by-election between the now incumbent Conservative Don Stewart and Liberal staffer Leslie Church. If I had to bet on a Conservative loss of any seats from dissolution, this would probably top the list. Unless a huge actual upset takes place (I will die on the hill that the by-election was not an upset), then the Liberals seem comfortably poised to take this seat back. Exact by-election results and riding polls are not inputted on a riding-by-riding level in my model, but even if I did, the Liberals would still be projected for a comfortable win here as they are now.

Eglinton-Lawrence

Shifting north, Eglinton-Lawrence wasn’t on my radar provincially, as it’s been consistently competitive between the PCs and OLP, so applying universal swing and the lack of an NDP candidate last-minute in a self-inspired push for ‘strategic voting’ which failed spectacularly. It was an open seat with no dipper, and the OLP with Vince Gasparro still managed to lose it; the projection had it at OLP+11.5, the actual result was PC+0.4, with the PCs and Liberals gaining very similar net vote %. Vince Gasparro is trying again to win this seat, this time federally, trying to replace well-known MP Marco Mendicino. He is now leading over star Conservative Karen Stintz, a former notable and longtime councillor for the ward. While it’s more likely that Toronto votes as a block for the Liberals for the fourth election in a row, if that were not to be the case, the most likely scenario is Toronto-St. Paul’s and Eglinton-Lawrence, and the next two on the list to break from the Liberal Party.

York Centre

Continuing to move up the middle of the city, York Centre is the last in the three potential Conservative pickups (well, one hold) that could happen. Incumbent Ya'ara Saks is seeking re-election. She’s notable for claiming that the term ‘honk honk’ during the 2022 Freedom Convoy was code for ‘heil Hitler’.

Despite how you see it, I doubt this will affect much in her suburban Toronto riding. The bigger risk Saks is facing is against Roman Baber, a former PC MPP for this riding who was removed from the PC caucus in early 2021 for his opposition to COVID lockdowns. He moved federal quickly after he decided not to seek re-election as an Independent in 2022. Running for federal party leadership, Baber came fourth with 5% of both votes and points nationwide.

Results of the 2022 Conservative Leadership Race

Saks is in the lead in the riding but if Baber can pull provincial PC supporters, a hard feat for someone kicked from the party, he could put up a good fight or even win. This seat provincially went PC by a slightly larger margin than the Liberals federally in the model right now.

Taiaiako'n-Parkdale-High Park

The last riding in the Toronto quintet is Taiaiako'n-Parkdale-High Park, a historic Liberal stronghold on the federal level. Peggy Nash is the only NDP MP to serve this area, which puts a lot of pressure on Bhutila Karpoche, the former MPP for Parkdale-High Park. She’s trying to take this open seat against her rival in 2022, Karim Bardeesy. She is projected to lose, but considering her provincial support, this could be an upset with her notability locally and in the large Tibetan community in the riding. She’s been campaigning in this riding very heavily, but with the unfortunate NDP polling across Toronto, Ontario, and Nationwide, it’s unlikely she picks this seat up.

Aurora-Oak Ridges-Richmond Hill

Back in York Region, Aurora-Oak Ridges-Richmond Hill could be in a similar circumstance to Markham-Unionville, as the Conservatives also accused a loss in this seat to foreign election interference. This is also one that flips around, and it’s expected to be another rare seat that pushes against the Liberal trend. There’s a large visible minority population in this riding, and with much of the rest of York Region, it’s a high Chinese and East Asian population. This riding tends to vote with Markham-Unionville, but this time it could split because of local factors in Markham. If East Asians swing to the CPC, this seat will very likely flip back to former MP Costas Menegakis, running for the Conservatives, trying to retake this seat. Polling out of York Region has the Liberals and Conservatives neck and neck, and this seat could trend Conservative if that support isn’t concentrated, but we can only make educated guesses until then. The model’s prediction in Aurora-Oak Ridges-Richmond Hill is a Liberal hold, electing Leah Taylor Roy for the second time.

Sault Ste. Marie-Algoma

Getting out of the GTA, two northern ridings are ones to watch on election night. One of them is Sault Ste. Marie-Algoma, a controversial mix of the former ridings of Algoma-Manitoulin-Kapuskasing (NDP) and Sault Ste. Marie (LIB), although ironically in the notional results, the Conservatives led here if this riding existed in 2021. The NDP made a big fuss during the redistribution because this seat effectively shuts them out here, worsened by the fact that locally well-liked and longtime MP for Algoma-Manitoulin-Kapuskasing, Carol Hughes, isn’t seeking re-election, she served as the MP since 2008. Laura Mayer, her replacement in the riding, isn’t expected to be in contention here, and local media have negatively reported on Hugh Stevenson for his campaign tactics. This leaves incumbent (from the former riding of Sault Ste. Marie) Terry Sheehan leading here by a comfortable margin. Now, this seems like a write-off, I know, but you never know what’s going to happen in the north, both just in Ontario and in northern ridings nationwide, take a look at Bulkley Valley-Stikine, Athabasca, Timmins, Torngat Mountains, The Territories, etc. These small ridings (population-wise) sometimes have limited online media reach, so when they swing, they swing hard. Don’t write this one off, and this is a geographically divided riding between urban Soo and rural Algoma. I don’t personally think this riding will be safe, Liberal, but we will see in just a couple of days, ridings like these rarely fit in easy, simple uniform swings that modellers place on ridings.

Kapuskasing-Timmins-Mushkegowuk

The other northern seat on the list, Kapuskasing-Timmins-Mushkegowuk, is the new version of Timmins-James Bay. Like in Algoma, longtime NDP MP Charlie Angus is not seeking re-election, he’s served as the MP since 2004. He’s been known as a fierce indigenous advocate and an extremely hard worker, who’s been one of the most influential MPs during his career. Before announcing he wouldn’t seek re-election in 2024, this seat was often projected to go Conservative. Only recently have the Liberals made a recovery here, driven by their recovery in polling in Ontario and among indigenous voters. The Liberals, with Steve Black, his second try at getting this seat, are currently in a razor-thin lead. Steve Black is well-known in Timmins, serving as a councillor, Mayor, and has run for the federal riding in 2021 and 2025, along with running in 2014 provincially. He’s leading over Gaétan Malette, who has a long history in forestry, agriculture, and mining, some of the three most important issues of this riding. He’s not unfamiliar with politics, being the campaign manager for Timmins MPP George Pirie’s run in 2022, which was arguably the biggest recent Ontario riding upset, knocking off longtime MPP Gilles Bisson, who served the area for over three decades. Attempting to defend this seat for the NDP is Nicole Fortier Levesque, a former mayor and councillor of Moonbeam, a small town of about a thousand. Like I said in the last section: do. not. write. this. off. even provincially, just a few weeks ago, one of the biggest misses in my model was Mushkegowuk-James Bay, this riding, but excluding much of the southeast and Timmins. Small riding, popular mayor for the PCs, yada yada, read about it here, but my projection was PC+11.4, the result? NDP+0.1, an eight vote margin. Again, anything can happen in the north, maybe this’ll be an NDP hold despite nearly half of their support leaving? We can only wait and find out.

Kitchener Centre

Back to more predictable ridings in Southern Ontario, Kitchener Centre will be the Green Party’s litmus test. The party has been deeply struggling since 2020 and could see its lowest vote share ever since Elizabeth May’s ascension to the leadership in 2008. The party was kicked out of participating in the debates this time, and polling has barely budged in 5 years. The federal party is lagging and struggling, and its two-person caucus could be down to one or even zero. Most people know Elizabeth May, MP for Saanich-Gulf Islands, but less know about Mike Morrice in Kitchener Centre. He ran in 2019, increasing the Green vote share from 3% to 26% and then won in 2021 thanks to the Liberal MP Raj Saini dropping out after allegations of sexual harassment were revealed.

The Liberal collapse here allowed the Greens to gain this seat even in an election that didn’t work in their favour with unpopular leader Annamie Paul. In 2021, nationwide, the party lost almost two-thirds of its support. Provincially, this seat has become as much of a Green bastion as Saanich-Gulf Islands with May. Greens won over half of the vote in the 2025 General, and when the Greens first picked this seat up in 2023, they won with 48%. The 2025 Ontario election wasn’t necessarily a great position for the Greens; they went down over 1% (nearly a quarter of their 2022 support). This may spark hope for the party federally in this seat, but it’s not exactly a parallel. The federal Greens are projected to hold relatively close to their 2021 result, which was noted as an abysmal failure for the party at the time. If Kitchener Centre swings away from the Greens, it could spell trouble out west for Elizabeth May and Paul Manly.

Hamilton Centre

In the Golden Horseshoe, Hamilton Centre is the crux of this region and the support for the NDP. Hamilton Centre is a safe NDP riding in normal circumstances, with long NDP histories on the federal and provincial levels. It’s a heavily working-class riding and one that will easily tell us on election night the effects of NDP incumbents and the support among NDP safe seats more generally. It’s been NDP since its creation in 2004, with incumbent Matthew Green, a notable voice on the left of the NDP, serving since 2019. Green could face a tough challenge if this is one of the ridings where the Liberals are taking… a fifth, a quarter, a third?? of NDP support as indicated by various polling. If the issue of tariffs is the primary voter motivation here, is the NDP the one to court those voters? It’s hard to say. Green is currently in the lead with his large amounts of local notoriety above Aslam Rana, an engineer who’s been connected to major infrastructure projects in Ontario.

Hamilton Mountain

Like Hamilton Centre, the issues in Hamilton Mountain (just south of Centre) are relatively similar. This riding has NDP roots, previously represented by the party from 2006 to 2021. NDP MP Scott Duvall didn’t seek re-election in 2021, which probably played a big role in why they lost this seat to Liberal Lisa Hepfner, a local journalist. This time, Hepfner is trying to get re-elected in this seat, making her the second Liberal to get more than one term in this riding. Going against her is local heavyweight Monique Taylor, who first ran in the provincial seat in 2011, beating the incumbent, and serving until she moved federal and didn’t reoffer in 2025, which this seat promptly flipped to the PCs with the NDP dropping almost 20% of the vote from 2022 and landing in third. Of the 3 NDP MPPs in Ontario (Monique Taylor, Bhutila Karpoche, Joel Harden) trying their hand to gain a federal seat, Taylor has the best chances. If any seat will go against the trend and flip Liberal → NDP, I’d place my bets on this riding. Also in the running is Ken Hewitt, former Mayor of Haldimand (outside Hamilton entirely), best known for his loss against Bobbi Ann Brady in 2022, losing almost 30% of the vote; Brady won 35% in that election.

Peterborough

Finally out of the grips of the GTHA for the rest of the list, we’re starting in Peterborough, one of the least Conservative rural seats in Southern Ontario. This riding was a bit of a hint towards a greater rural/urban divide growing in Canadian politics. Liberals won here (the former riding of Peterborough-Kawartha) in 2015 and 2019, but lost in 2021 and looking at the poll-by-poll maps, Conservatives strengthened in that time among rural parts of the riding. This riding is also somewhat of a bellwether, voting with the winning party in every election since the late 50s, with the exceptions of 2021 and 1963. This riding seems like it’ll fit back into this trend in 2025, with the Liberals leading in the model in this riding with Emma Harrison, a farmer, which could help push back against a Conservative win with increasing polarization, which would let Michelle Ferreri have another term in Ottawa. She is a former Peterborough journalist.

London-Fanshawe

On the eastern end of London, London-Fanshawe is another NDP-held riding at risk of flipping around to the CPC or LPC. A true three-way race, this riding has been targeted by the main parties for some time now. Interestingly, the Liberals have not been putting on strong campaigns among their candidates in NDP-held seats, but this one is different, with the Liberals pulling a lot of resources to try and win this seat and break the Mathyssen dynasty that’s held this riding since 2006. The NDP has actually gone up in vote share every single election since then, with a notable exception in 2015, the Trudeaumania mixed with a star candidacy with a former MPP trying to pick up the seat a decade ago. The NDP isn’t expected to expand their vote share this time, but with Liberal Najam Naqvi and Conservative Kurt Holman being paper candidates, Lindsay Mathyssen seems poised to hold onto this seat with her notoriety, although it is still a close three-way race.

Kingston and the Islands

Back in Eastern Ontario, the battle for Kingston and the Islands is a battle of Mayors. The seat has flipped back and forth since it first became a riding, but recently it’s been held by notable Liberals Peter Milliken, Ted Hsu, and Mark Gerretsen. Gerretsen has been the MP since 2015, and interestingly, one of the only seats where the NDP has come second in non-major urban Ontario in 2019 and 2021, thanks to weak Conservative candidates. This election, however, could cause a big shift in the local dynamics here with longtime popular Mayor Bryan Paterson running for the Conservatives. Both Gerretsen and Paterson have served as mayor of Kingston, and Gerretsen was a councillor as well. They’ve also had their fair share of controversy, but it could be close. This riding is on this list to determine how much local candidates matter. It’s an issue in modelling every election, but federally, it can play a big role as polls can’t capture small local swings well. If this riding shifts Conservatives further than the polls show, then some weird results could happen elsewhere where candidacies matter a lot.

Windsor West

On the other side of the province, Windsor West is a similar riding in which tariffs are a big issue. This riding is also an NDP incumbent riding, with longtime NDP MP Brian Masse, who’s held it since 2002, seeking another term in the House of Commons. Unlike the other NDP incumbents on this list, Masse has been underwater for a while. Now, there’s always a chance, he’s running against paper candidates, and that could help him, but this is one I personally will be keeping my eye on for candidate selection over national party choice. Richard Pollock is the Liberal currently in the lead, he’s a federal crown prosecutor.

Bay of Quinte

Finishing off the list, the last three ridings are in Eastern Ontario, the first one in Bay of Quinte, not far from Kingston and the Islands. Bay of Quinte is a bit of a litmus test riding, as it votes Conservative outside of Liberal majority governments. The riding is similar to Peterborough, in which there’s a large dominant town, while also incorporating large rural areas. The riding was Liberal from 2015 to 2019, before flipping Conservative in 2021. The last time the Liberals held this seat was Jean Chrétien’s three majority governments spanning the late 90s to early 2000s. The model currently has both a Liberal majority government and a red Bay of Quinte thanks to a fall in the NDP. Chris Malette is a Councillor in Belleville, the main town in Bay of Quinte, and is expected to gain this seat. However, with big margins of error, this seat is still very open to go Conservative with the incumbent and also former Belleville councillor Ryan Williams. There’s no PPC candidate, and it’s a rural seat, so they could break from their trend here.

Prescott-Russell-Cumberland

Another rural seat in the east, Prescott-Russell-Cumberland (formerly known as Glengarry-Prescott-Russell), could be a Yarmouth situation in which a long-held Liberal seat flips Conservative. This riding is the only majority francophone riding in Ontario, over 60% speak French. There’s no incumbent in this seat, but Giovanna Mingarelli is expected to hold the seat for the Liberals. It’s voted Liberal, both with Anglophone and Francophone leaders alike, but with Liberal support among French speakers and Quebecois struggling compared to Trudeau 4 years ago, a weird result could happen in this riding. It’s a rural seat that’s voted consistently PC with Ford provincially and with Conservative candidate Julie Séguin, a councillor in the riding, this riding could be competitive. And I hate to keep mentioning it, but if rural/urban polarization causes a polling (and then modelling) miss as it has in recent elections, this riding could be even closer. It was Conservative during Stephen Harper’s Prime Ministership with Pierre Lemieux.

Nepean

Rounding it off in suburban Ottawa, Nepean is an interesting case study of sorts on how much Ottawa has trended left federally. It’s a fact that it’s been happening provincially, but it’s not as clear federally. Pierre Poilievre previously represented this riding when it was more rural and paired with his current riding of Carleton. When the riding was created in 2015, Chandra Arya won in a big swing and has held it since. He’s been slowly getting distant from the federal party. Since 2021, he’s spoken on Sikh separatist issues in India on his own terms like arguing against ‘Khalistani extremists’ or saying Hindu Canadians are ‘fearful’ of Sikh separatist supporters after the assassination of Hardeep Singh Nijjar. In 2024, Arya travelled to India and met with the Prime Minister, Narendra Modi, which made Arya face backlash amidst the diplomatic issues. He continued to dig his political grave when he announced he was running for leader of the Liberal Party in 2025. He stated that despite his inability to speak French, it doesn’t matter to Francophone Canadians. He was barred for running for leader of the party, being accused as unfit.

Two months after being barred from running for party leader, his nomination to seek re-election in Nepean as a Liberal was revoked, and two days later, it was announced that Prime Minister Mark Carney would be the candidate in the riding. Carney is expected to hold this seat for the Liberal Party over Conservative Barbara Bal.

Thank you for reading part 3 in the series! I’m trying to get these out as quickly as I can, so thank you for supporting my work. You can subscribe and share using the buttons: