Norðurá is a river that runs the length of Norðurárdalur valley in Skagafjörður, Iceland, where it creates extensive sandbars on the valley floor.

[1] The river joins the Héraðsvötn below Flatatunga.

[2] Many tributaries flow into the Norðurá, some located in massive ravines, including Kotá, Valagilsá, Horná, Heiðará, Grjótá, Króká, Egilsá, Stóralækur rivers.

[3]