Pudasjärvi is a Finnish city located in the northern part of the province of Northern Ostrobothnia, in the middle reaches of the Iijoki River. Pudasjärvi belongs to the Oulunkaari region. Its neighboring municipalities are Ii, Oulu, Posio, Puolanka, Ranua, Suomussalmi, Taivalkoski and Utajärvi. The center of Pudasjärvi is called Kurenalus.

Pudasjärvi has a total area of ​​5,867.27 km², of which 228.99 km² is inland water area. Of the municipalities outside Lapland, Pudasjärvi has the largest area. When the municipalities of Lapland are included in the comparison, Pudasjärvi is the eighth largest municipality in Finland.

Pudasjärvi became a city on January 1, 2004. Of the municipalities using the name City, Pudasjärvi is the second largest in terms of area after Rovaniemi, and with a population density of only 1.39 inhabitants per square kilometer, Pudasjärvi is the least populated municipality in Finland. Despite the designation, Pudasjärvi is a rural municipality according to a statistical grouping of municipalities, as its degree of agglomeration is only 50.8 per cent (in 2016).