Evijärvi is a municipality of Finland. It is located in the Southern Ostrobothnia region. The municipality has a population of 2,292 (31 December 2023) and covers an area of 390.71 square kilometres (150.85 sq mi) of which 36.7 km (14.2 sq mi) is water. The population density is 6.47 inhabitants per square kilometre (16.8/sq mi).

Neighbouring municipalities are Kauhava, Kronoby, Lappajärvi, Pedersöre and Veteli.

The municipality is unilingually Finnish.

Notable people born in Evijärvi

• Jalmari Linna (1891–1954)
• Aleksi Kiviaho (1913–1986)
• Ilmari Linna (1917–1981)
• Tea Ista (1932–2014)
• Esko Ahonen (1955–)