Kolari is a municipality of Finland at the Swedish border, which follows the Torne River, the longest free-flowing river in Europe.
It is located in the region of Lapland. The municipality has a population of 3,930 (31 August 2024) and covers an area of 2,617.87 square kilometres (1,010.77 sq mi) of which 59.15 km2 (22.84 sq mi) is water. The population density is 1.54 inhabitants per square kilometre (4.0/sq mi).
Neighbouring municipalities are Muonio, Pello, Kittilä, Rovaniemi in Finland and Pajala Municipality in Sweden.
The municipality is unilingually Finnish.
Kolari railway station is the northernmost station in Finland.
Ylläs, one of the most popular ski resorts in Finland, is located in Kolari. The area also features the country's largest bog with a thousand-year-old forest.