Posio is a municipality of Finland. It is located in the province of Lapland. The municipality has a population of 2,876 and covers an area of 3,5…Posio is a municipality of Finland. It is located in the province of Lapland. The municipality has a population of 2,876 and covers an area of 3,544.90 square kilometres of which 506.14 km² is water. The population density is 0.95 inhabitants per square kilometre. Neighbour municipalities are Rovaniemi, Kemijärvi, Ranua, Salla, Kuusamo, Taivalkoski and Pudasjärvi.