Sumiainen is a former municipality of Finland.
It is located in the province of Western Finland and is part of the Central Finland region. The municipality had a population of 1,293 (2003) and covered an area of 307.93 km² of which 77.34 km² is water. The population density was 5.6 inhabitants per km².
Sumiainen consolidated to Äänekoski together with Suolahti in 2007.
The municipality was unilingually Finnish. The municipality has previously also been known as "Sumiais" in Swedish documents, but is today referred to as "Sumiainen" also in Swedish.
Coordinates: 62°39′25″N 26°02′50″E / 62.65694°N 26.04722°E
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