Värtsilä /ˈværtsilæ/ is a former municipality of Finland. It merged with Tohmajärvi in 2005.
Värtsilä was located in the province of Eastern Finland and was part of the North Karelia region. The municipality had a population of 647 (2003) and covered an area of 143.81 square kilometres (55.53 sq mi) of which 7.88 km2 (3.04 sq mi) was water. The population density was 4.8/km2 (12/sq mi).
The main language spoken in Värtsilä is Finnish but new settlers from Russia and people evacuated from the lost Karelian areas after the Second World War form Russian and Karelian speaking minorities.
In addition to the current village, Värtsilä used to include the urban settlement of Vyartsilya (Russian: Вяртсиля), which since 1944 has belonged to Russia.
Coordinates: 62°12′04″N 30°36′37″E / 62.2011111111°N 30.6102777778°E