- For other places with the same name, see Pyhäjärvi (disambiguation).
Pyhäjärvi is a town and municipality in the Southern Oulu region.
The municipality has some 5,500 inhabitants on 1,500 km². It is named after the lake Pyhäjärvi ("sacred lake", one of many by that name). The river Pyhäjoki flows from the lake to the Bay of Bothnia of the Baltic Sea, with its mouth in Pyhäjoki.
The town features the Pyhäsalmi mine, the deepest in Europe, with the probably deepest located sauna worldwide.
National roads 4 (E75) and 27 pass through the municipality.