Photo: P199 · CC BY-SA 3.0A higher share of households in buildings of five or more storeys than 82% of Canadian towns, at 12%
Across Canada’s towns, 27% of households are one person living alone; in Sarnia, 34%. About 80,539 people lived in the town in July 2025, Statistics Canada estimates. Census figures put residents aged 65 and over at 25% in the town. The median age locally is 46, higher than in 72% of Canadian towns.
A +1% change since 2016: slower than 73% of Canadian towns
The figures are the 2021 Census’s, except where another date is given. How the population moved between the last two censuses, and since.
Change, 2016 to 2021
Statistics Canada’s estimate for July 2025 is 12% higher again. Across Canada’s towns, the typical town changed +4%; across Ontario’s towns, +6%.
Only 15% of residents are under 15 in Sarnia
Residents by five-year age band, each beside the typical town (the tick).
60–64 is the most common age band: 8% of residents. On average, 16% of residents are under 15 across Canada’s towns.
Median age of Canadian towns of 2,500+
■ Sarnia, 46. The typical town is 42.
Broad ages · share of residents
Women and men · all residents
51% women, 49% men
About 95 men for every 100 women.
2.2 people per household, fewer than in 74% of Canadian towns
Household types, then household sizes.
Against Ontario’s towns and Canada’s towns
People per household
Canada’s towns.
9.4% of households are one-parent families, against 8.2% across Canada’s towns.
In Sarnia, 10% of residents 15 and over live common-law, fewer than in 54% of Canadian towns
Married, common-law, single: residents 15 and over.
Marital status · residents 15 and over
Singles who have never married make up 27% of adults, beside a typical 27%. Here, 45% of residents 15 and over are married. Across Canada’s towns, the share of common-law partners is 11%.
Renter households: 32%, a higher share than 63% of Canadian towns
Dwelling types, tenure and age of the housing. Prices, rents and shelter costs are on Cost of living.
Type of home
Owners and renters · share of households
When homes were built · share of homes
36% of homes were built before 1961 and 11% in 2001 or later. Typically, a quarter of households rent their home across Canada’s towns. Across Canada’s towns, the share of households in single-detached houses is 64%; Sarnia has 67%.
A median household income of $77,500 a year
Census incomes are for 2020, the year before the census, when CERB and other pandemic benefits topped up many households. Total household income: the median household, and the spread from low to high.
Households by income · share of households
The middle household in Sarnia had $77,500 before tax, 10% below the median across Canada’s towns ($86,000). Across Ontario’s towns the median is $91,600. Pandemic payments such as CERB reached 27% of income recipients here, against 28% in the typical town.
12% of residents are immigrants
Where immigrants were born and when they came, and how recently residents moved in.
Immigrants, by continent of birth · share of all residents; the bar runs to 35%
When immigrants arrived · share of immigrants
Citizenship and moving · share of residents
Immigrants here were most often born in Europe (53%), then in Asia (24%). 11% lived at another address a year earlier, more than the typical 11% across Canada’s towns. Recent arrivals are 15% of immigrants (2011 to 2021), beside 27% across Canada’s towns.
40% of residents said they have no religion, more than in 64% of Canadian towns
Visible minority and Indigenous identity, then religion.
Visible minority and Indigenous identity · all residents
Religion · all residents
The share of visible minority residents is 8.3%, against 15% across Canada’s towns. The wider picture: just over a third of residents said they have no religion across Canada’s towns. For Sarnia, the census puts Indigenous residents at 4.2%.
88% have English as their mother tongue; 7.4% also speak French
The official languages residents can speak, and the ones they learned first.
Can hold a conversation in · share of all residents
Mother tongue · share of all residents
At 2.2%, the share of residents whose mother tongue is French is in line with the figure across Canada’s towns.
Below 64% of Canadian towns: 21% of residents 25 to 64 hold a bachelor’s degree or higher
Highest certificate, diploma or degree of residents aged 25 to 64.
Highest qualification · residents 25 to 64
Without any certificate: 7.7% of 25- to 64-year-olds (typical: 9.5%).
A job for 48% of residents aged 15 and over
May 2021 was still a pandemic month: the census’s work figures reflect that. Work, briefly: employment, unemployment, participation and working from home. Jobs, industries and the commute are on Work & commute.
At 48%, fewer residents are in work than the typical 58% across Canada’s towns, and 25% are 65 or over.
41 towns of 60,874 to 107,345 people: this is the 8th oldest
The Canadian towns closest in population, from youngest to oldest.
Median ages climb from 34 (Grande Prairie) to 51.6 (Lindsay) across the group. Closest in median age to Sarnia are Welland (45.2), Belleville (45.2), Chomedey (46.2) and Saint-Hyacinthe (46.4).
Sarnia and its 5 nearest towns: 2 of them are older
The closest towns, coloured by how old their residents are. Sarnia has few close neighbours with figures, so the list reaches 4–22 km out.
| Town | People | Away | Median age | 65+ | Immigrants |
|---|---|---|---|---|---|
| Sarnia | 80,539 | — | 46 | 25% | 12% |
| Point Edward | 1,989 | 3.6 km | 55.2 | 32% | 9.3% |
| Plympton-Wyoming | 9,548 | 19.6 km | 45.6 | 22% | 7.1% |
| Corunna | 15,872 | 19.8 km | 44.8 | 23% | 5.1% |
| Petrolia | 6,422 | 21.3 km | 42.8 | 24% | 5.6% |
| Enniskillen | 3,174 | 22.1 km | 47.2 | 23% | 6.3% |
Health, work, housing and schools
What this data can and can’t tell you
- What these tables don’t give. Missing from the census as published: unpaid care, cars and internet access, and the shift in each age band since 2016. Ethnic origins past visible minority and Indigenous identity aren’t charted here.
- The census’s own words. Indigenous identity, immigrant status and religion are as residents answered them. “Visible minority” follows the Employment Equity Act, meaning people other than Indigenous peoples who are non-white in colour or race. We compare these figures across towns; none is a label for a town.
- Against Ontario’s towns and Canada’s towns. Provincial and national yardsticks: Ontario’s towns and neighbourhoods of at least 2,500 residents, and all Canadian towns of that size. No whole city and no First Nations reserve is in either median.
Questions about Sarnia’s residents
What is the median income in Sarnia?
The median household in Sarnia took in $77,500 in 2020, against $86,000 across Canada’s towns.
What is the population of Sarnia?
Sarnia had about 80,539 residents in July 2025, Statistics Canada estimates; the 2021 Census counted 72,047, about the same as 2016.
What is the average age in Sarnia?
A median age of 46, older than 72% of Canadian towns. Children under 15 make up 15%, and people 65 and over 25%.
Is Sarnia bilingual?
7.4% of residents can speak both English and French (typical across Canada’s towns: 7.5%); 0.1% speak French only and 92% English only. French is the mother tongue of 2.2%.
How diverse is Sarnia?
12% of residents are immigrants (Canada’s towns: 17%); 8.3% belong to a visible minority and 4.2% have an Indigenous identity.
What religion are people in Sarnia?
57% are Christian and 40% have no religion; 3.7% follow another religion.
Is Sarnia good for families?
Under 15: 15% (Canada’s towns: 16%). Couple families: 49% of households. One-parent families: 9.4%. Schools near Sarnia are on its Schools page.
Sources: Statistics Canada, Census Profile, 2021 Census of Population · Statistics Canada, population estimates for 1 July 2025 (table 17-10-0155). Under the Statistics Canada Open Licence.
Adapted from Statistics Canada (Census of Population 2021, population estimates 2025, 2021 census boundaries) under the Statistics Canada Open Licence; this does not constitute an endorsement by Statistics Canada. Neighbourhood names in some cities © OpenStreetMap contributors (ODbL).