Kauhajoki is a town and municipality of Finland. It is located in the province of Western Finland and is part of the Southern Ostrobothnia region, 59 kilometres southwest of the city of Seinäjoki. The population of Kauhajoki is 12,572 and the municipality covers an area of 1,298.98 km² of which 16.46 km² is inland water. The population density is 9.68/km². The town is unilingually Finnish.