Terjärv is located in the province of Western Finland and is part of the Ostrobothnia region.

The former municipality is bilingual, with a large majority Swedish-speaking and the minority Finnish.

Being 43 kilometres (27 mi) by air from port city Jakobstad at the nearest coastline,[7] the village is among the further inland settlements of Swedish-speaking Finland.

Others are Högnabba, Djupsjöbacka, Kortjärvi, Dövnäs, Kolam, Emet and Drycksbäck.

There are also places like Särs-Backman or Skogsbyn, Klubbi, Granö, Skullbacka, Nabba, Sågslamp, Kaitås, Emas, Lotas, Peckas, Sandvik, Grannabba, Långbacka, Lytz, Vistä, Furu, Svartsjö, Myngels, Manderbacka, that cannot be called villages but are boroughs of some of the main villages.