Isokyrö is a municipality of Finland. It is located in the South Ostrobothnia region, 43 kilometres from Vaasa. The municipality has a population …Isokyrö is a municipality of Finland. It is located in the South Ostrobothnia region, 43 kilometres from Vaasa. The municipality has a population of 4,320 and covers an area of 356.91 square kilometres of which 2.79 km² is water. The population density is 12.2 inhabitants per square kilometre.