Kyyjärvi (Finnish pronunciation: [ˈkyːˌjærʋi]; lit. "adder lake") is a municipality of Finland. It is located in the Central Finland region, about 120 kilometres (75 mi) northwest of Jyväskylä. The municipality has a population of 1,315 (31 July 2020) and covers an area of 469.61 square kilometres (181.32 sq mi) of which 21.39 km2 (8.26 sq mi) is water. The population density is 2.93 inhabitants per square kilometre (7.6/sq mi). The municipality is unilingually Finnish.
Neighbouring municipalities are Alajärvi, Karstula, Kivijärvi, Perho and Soini. The municipality centre is located on the shores of Lake Kyyjärvi. Little villages Hokkala, Koskimäki-Huhtala, Kumpula, Noposenaho, Hokkasenaho, Nurmijoki, Oikari, Peuralinna, Pölkki, Saunakylä and Vehkaperä are living mostly from primary production (farming and forestry). Due to its location on the crossroads of two main Finnish roads (Valtatie 13 and 16) the municipality has also a remarkable number of services and little companies compared to its size.
The world's first district heating grid that uses only EKOenergy labelled renewable energy is located in the town center of Kyyjärvi.
The origin of the name of Kyyjärvi is unknown but there are few theories of it. The first part of the name, "kyy", is Finnish word for adder (Vipera berus), a venomous snake. Järvi is Finnish word for lake. Adders can be found in Kyyjärvi, as everywhere in Finland. Another theory is that the first citizens moved to the area from the lake Kyyvesi and gave the name Kyyjärvi for their new home area and lake.
There are all together 46 lakes in Kyyjärvi. Biggest lakes in Kyyjärvi are Lake Kyyjärvi, Heinuanjärvi and Kirvesjärvi.
Aila Paloniemi, Member of the Parliament of Finland