Seinäjoki has a population of 66,848, making it the 16th largest place we list in Finland. It is in South Ostrobothnia.
Seinäjoki holds 1.2% of Finland's 5,621,739 people. Helsinki, the largest place we list there, is 9.9 times its size. Twenty years earlier the World Gazetteer recorded 32,149, a rise of 108%.
The 2005 figure comes from the World Gazetteer archive restored on this site. The two sources may draw the settlement's boundary differently, so treat the change as indicative rather than exact. Why figures differ.
Nearby in size
| Place | Region | Population |
|---|---|---|
| Lappeenranta | South Karelia | 72,909 |
| Vaasa | Ostrobothnia | 69,819 |
| Hämeenlinna | Kanta-Häme | 68,473 |
| Rovaniemi | Lapland | 65,670 |
| Porvoo | Uusimaa | 51,853 |
| Mikkeli | South Savo | 51,661 |
Figures are the latest available in GeoNames (CC BY 4.0), which draws on national censuses of varying dates — treat them as recent, not same-year. Country totals are UN World Population Prospects 2024 (medium variant) where the UN lists the country separately; the handful it reports under a parent state keep a GeoNames figure and are marked as such. Sources & method.