Viitasaari is a Finnish town and municipality located in the Central Finland region. It is located between the neighbouring municipalities of Pihtipudas to the north and Äänekoski to the south. The town has a population of 5,695 (31 December 2025) and covers an area of 1,589.13 square kilometres (613.57 sq mi) of which 340.43 km2 (131.44 sq mi), or 21%, is water. There are altogether 230 lakes in Viitasaari. The biggest lakes are Lake Keitele, Lake Kolima and Muuruejärvi. The population density is 4.56 inhabitants per square kilometre (11.8/sq mi).