Multia is a municipality of Finland.

It is located in the province of Western Finland and is part of the Central Finland region. The municipality has a population of 1,745 (30 June 2015) and covers an area of 765.62 square kilometres (295.61 sq mi) of which 32.37 km (12.50 sq mi) is water. There are all together 146 lakes in Multia. Biggest lakes in Multia are Sinervä, Tarhapäänjärvi and Sahrajärvi-Pienvesi. The population density is 2.38 inhabitants per square kilometre (6.2/sq mi).