| Koillismaa Koillismaan seutukunta |
|
|---|---|
| — Sub-region — | |
| Country | Finland |
| Region | Northern Ostrobothnia |
| Population (2011) | |
| • Total | 20,843 |
| Time zone | EET (UTC+2) |
| • Summer (DST) | EEST (UTC+3) |
Koillismaa is a subdivision of Northern Ostrobothnia and one of the Sub-regions of Finland since 2009.