Haapavesi-Siikalatva subregion:
Haapavesi, Pyhäntä, Siikalatva

Nivala-Haapajärvi subregion:
Haapajärvi, Kärsämäki, Nivala, Pyhäjärvi, Reisjärvi

Ylivieska subregion:
Alavieska, Kalajoki, Merijärvi, Oulainen, Sievi, Ylivieska

Area: 10 000 km²
Population: 87 000
Main centre: Ylivieska (13 800 inhabitants)

Oulu South is an area in southern part of Oulu Province comprised of 3 subregions and 14 municipalities.