Isiolo has a population of 78,650, making it the 35th largest place we list in Kenya. It is in Isiolo County.
Isiolo holds 0.13% of Kenya's 58,636,412 people. Nairobi, the largest place we list there, is 56 times its size. Twenty years earlier the World Gazetteer recorded 33,207, a rise of 137%.
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 |
|---|---|---|
| Athi River | Machakos County | 81,302 |
| Meru | Meru County | 80,191 |
| Nyeri | Nyeri County | 80,081 |
| Ukunda | Kwale County | 77,686 |
| Kiserian | Kajiado County | 76,903 |
| Kilifi | Kilifi County | 74,270 |
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.