Vuolijoki is a former municipality in Finland. The municipality was consolidated with the city of Kajaani in the beginning of year 2007.
Vuolijoki was located in the province of Oulu and was part of the Kainuu region. In 2004 the municipality had a population of 2,643 and covered an area of 895.20 km² of which 203.05 km² was water. The population density was 3.8 inhabitants per km².
The municipality was unilingually Finnish.
Coordinates: 64°11′00″N 26°59′50″E / 64.18333°N 26.99722°E