Haakon VI of Norway (Norwegian: Håkon, Swedish: Håkan; 1340–1380), also known as Håkan Magnusson, was King of Norway from 1343 until his death and King of Sweden between 1362 and 1364. He is sometimes known as Haakon Magnusson the Younger to distinguish him from his great-grandfather, Haakon V (reigned 1299–1319). Upon his death in 1380, Haakon was succeeded by Olaf, with Margaret as regent. Olaf died childless seven years later, and Haakon's widow proceeded to assert authority over all three Scandinavian kingdoms as their first female monarch.