Ristijärvi

Ristijärvi () is a municipality of Finland. It is part of the Kainuu region. The municipality has a population of (), which makes it the smallest municipality in Kainuu in terms of population. It covers an area of of which is water. The population density is . The municipality is unilingually Finnish.

thumb|right|The Kiehimänjoki river Kiehimänjoki is a river of Finland. It flows for . The river begins from lake Iijärvi in Paltamo in Kainuu region and ends to the lake Oulujärvi, from which the waters flow through the Oulujoki River into the Gulf of Bothnia. The river drains a chain of lakes that originates in the municipalities of Suomussalmi and Hyrynsalmi in Kainuu ().