The Battle of Siikajoki () was fought between Swedish and Russian troops on April 18, 1808 at Siikajoki, near Oulu, Finland. During the first stage of the Finnish War the Swedish commander Wilhelm Mauritz Klingspor had decided to retreat from southern Finland, so that the Swedes would gain time, and more troops could be moved to Finland via Tornio. The move was also made in case the Danes would take the opportunity attack Sweden. The Battle of Siikajoki is described in the poem "Adlercreutz" in Runeberg's epic Tales of Ensign Stål.