Iseyin has a population of 365,300, making it the 38th largest place we list in Nigeria. It is in Oyo State.
Iseyin holds 0.15% of Nigeria's 242,431,832 people. Lagos, the largest place we list there, is 42 times its size. Twenty years earlier the World Gazetteer recorded 340,686, a rise of 7%.
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 |
|---|---|---|
| Makurdi | Benue State | 390,000 |
| Ondo | Ondo State | 375,000 |
| Umuahia | Abia State | 370,000 |
| Yenagoa | Bayelsa State | 365,000 |
| Gboko | Benue State | 365,000 |
| Ijebu Ode | Ogun State | 360,000 |
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.