The Political Record · Federal electoral districts

Markham—Stouffville

Federal riding · ON · No. 35056 · 2023 representation order
Fig. 1 — Markham—Stouffville, 2023 boundaries.
Member
Helena Jaczek Liberal
2025 result
Liberal hold by 3,760 votes
Turnout
69.2% of 89,529 electors
Population
120,845 2021 census
Area
83 km²
Figures as of
2026-09-25
Distinctions · ranked against all 343 ridings
  • Decided before election day: On election-day polls alone another party led; advance and special ballots decided it · one of 27 of 34327
    Decided before election day
    On election-day polls alone another party led; advance and special ballots decided it · one of 27 of 343
  • Population, largest first: 120,845 people, 2021 census · 53rd of 343 in Canada53rd
    Population, largest first
    120,845 people, 2021 census · 53rd of 343 in Canada
  • Length of the ballot: 6 candidates stood · 61st of 343 in Canada61st
    Length of the ballot
    6 candidates stood · 61st of 343 in Canada
In brief
  1. Helena Jaczek held the seat for the Liberals by 3,760 votes (+6.1 points).
  2. 3% of today's riding was drawn from other ridings in 2023.
  3. On election day alone, the Conservatives led; advance and special ballots decided it.
  4. Share of households that own their home is the 15th highest of 343 ridings.
Illustration after: © House of Commons
Member of Parliament
Helena Jaczek
Liberal · first elected 2019-10-21 · 3 terms
  • Member: Health

IDid this riding change?

Yes. 3% of today's Markham—Stouffville came from ridings other than the old Markham—Stouffville.

Share of today's areaFormer riding
97.2%Markham—Stouffville 27% of it kept
2.8%Markham—Unionville 3% of it kept
How this is measured. Share of the current riding's area that came from each former riding, by intersecting the 2013 and 2023 boundary files. It is area, not population. Elections Canada counts 48 of 343 ridings as entirely unchanged.

IIThe 2025 result

Liberal hold
Elected
Helena Jaczek
Liberal
31,658
51.4% of valid votes
Margin
3,760
votes · +6.1 pts
Runner-up
Niran Jeyanesan
Conservative
27,898
45.3% of valid votes
Liberal 51.4% · Conservative 45.3% · New Democratic 1.8%
Turnout69.2% of 89,529 electors
CandidatePartyVotes%2021±
Helena JaczekLiberal31,65851.4%51.1%+0.3
Niran JeyanesanConservative27,89845.3%34.5%+10.8
Serena CheungNew Democratic1,1211.8%8.7%−6.9
3 further candidates, each under 1% of the vote
Myles O'BrienGreen4330.7%
René de VriesPeople's3930.6%
Shahzad AhmedOther1410.2%
The 2021 column is Elections Canada's official transposition of the 2021 result onto these 2023 boundaries. ± is the change in each party's share. It is not "swing": with four or more competitive parties there is no single pair to swing between.

IIIHow close was it, really

Swing needed to flip
3.0 pts
Half the margin: the share that would have had to move from first to second.
Third place vs. the margin
1,121 votes
New Democratic took fewer than the 3,760-vote margin.
Election-day polls won by others
93 of 183
4 polls ended in an exact tie.
Fig. 2 — Each square is one election-day poll: ■ won by the Liberals (86) · ■ won by another party (93) · ▨ tied (4).
Flip the seatHypothetical

It would have taken 1,881 voters switching from Liberal to Conservative — 3.1% of the 61,644 valid votes, 3.0 points — to change the result. No ballot was cast this way; this only moves votes between the top two.

Liberal31,658
Conservative27,898
Still Liberal by 3,760 votes. Actual margin: 3,760.

IVElection day versus advance

Only 55.5% of this riding's votes were cast at election-day polls. The rest were advance or special ballots. On election day alone, the Conservatives led here — the seat was decided by ballots cast before the day.

Election dayAdvance & specialGap
Conservative48.1%41.7%−6.4
Liberal48.0%55.6%+7.6
New Democratic2.0%1.5%−0.5
An association, not a cause. Voters who cast ballots before election day differed from those who turned out on the day. It does not say why. There is no poll-level turnout figure on this page: the elector count on a polling division includes people who voted in advance and were counted elsewhere.

VWhat kind of place this is

2021 Census, keyed to the 2023 representation order. Comparisons are against the median riding, not Canada as a whole. Each rule places this riding among all 343.

VIWhere it is

loading basemap…
Fig. 3 — Markham—Stouffville and its 4 neighbouring ridings.

The card

No. 35056ON · 2025
Markham—Stouffville
Helena Jaczek
Result
Liberal hold by 3,760
Turnout
69.2%
Population
120,845
Area
83 km²
Decided before election day: On election-day polls alone another party led; advance and special ballots decided it · one of 27 of 34327Decided before election dayPopulation, largest first: 120,845 people, 2021 census · 53rd of 343 in Canada53rdPopulation, largest firstLength of the ballot: 6 candidates stood · 61st of 343 in Canada61stLength of the ballot
One of 343The Political Record

A card exists for every one of the 343 ridings.

Every figure on it is the figure on this page: the 2025 result and margin, turnout, the 2021 census population, the area, and the distinctions ranked against all 343 ridings. The portrait is an illustration after the official House of Commons photograph.

Open a neighbour to collect the next one.