Oulujoki (municipality)  Oulujoki (formerly "Oulun maalaiskunta" or "Oulu Rural Municipality") is a former municipality of Finland. The municipality had a population of () and covered a land area of . Its neighbouring municipalities were Kempele, Kiiminki, Muhos, Oulu, Tyrnävä, Utajärvi and Ylikiiminki. The municipality was named after the river Oulujoki. The municipality of Oulujoki was dissolved in 1965, and its area was annexed to Haukipudas, Kempele, Kiiminki, Oulu, Oulunsalo, Tyrnävä, Utajärvi and Ylikiiminki. Upon the later municipal mergers of 2009 and 2013 the major part of the area of the municipality of Oulujoki is now part of Oulu.