Eric Magnusson (Old Norse: Eiríkr Magnússon; Norwegian: Eirik Magnusson) was the King of Norway from 9 May 1280 until 1299. He had been "rex iunior" (junior king) from 1273.
A prominent feature of Eirik's reign was war with Denmark, which was waged on and off from 1287 until 1295. A major motivation for this warfare was Eirik's claim on his mother's Danish inheritance. In 1287, he also entered into an alliance with a group of Danish nobles, most prominently Jacob Nielsen, Count of Halland and Stig Andersen Hvide, who were outlawed in Denmark for allegedly murdering the Danish king Eric V. Eirik gave the outlaws sanctuary in Norway in 1287. King Eirik himself led a large Norwegian fleet which, along with the Danish outlaws, attacked Denmark in 1289, burning Elsinore and threatening Copenhagen. Renewed naval attacks on Denmark were made in 1290 and 1293, before peace was made in 1295.
Eirik received the nickname "Priest Hater" from his unsuccessful relations with the church.
As Eirik died without sons, he was succeeded by his brother, as Haakon V of Norway.