Haapavesi is a municipality of Finland.

It is located in the province of Oulu and is part of the Northern Ostrobothnia region. The municipality has a population of 7,818 and covers an area of 1,085.79 km² of which 38.14 km² is water. The population density is 7.2 inhabitants per km².

The municipality is unilingually Finnish.

The town of 8 000 people is most known of the Haapavesi Folk Music Festival, which gathers fantastic folkmusicians together from all over the world. Haapavesi is also known from its great skiiers.