Äänekoski is an industrial town and municipality of Finland.

It is located in the province of Western Finland and is part of the Central Finland region. It is neighboured by Kannonkoski, Konnevesi, Laukaa, Saarijärvi, Uurainen, Vesanto and Viitasaari. The town has a population of 19,879 (30 June 2015) and covers an area of 1,138.38 square kilometres (439.53 sq mi) of which 253.84 km (98.01 sq mi) is water. There are altogether 170 lakes in Äänekoski. Biggest lakes are Keitele, Kuhnamo and Niinivesi The population density is 22.47 inhabitants per square kilometre (58.2/sq mi).