The Porsangerfjorden (; ; ) is a fjord in Finnmark county, Norway. The long fjord is Norway's fourth-longest fjord. It is located in the municipalities of Nordkapp and Porsanger and it empties out into the Barents Sea. The large island of Magerøya and the Porsanger Peninsula lie along the western shore of the fjord, and the Sværholt Peninsula lies along the eastern shore of the fjord.  Helnes Lighthouse sits at the mouth of the fjord, on the western coast.