Magnus Olafsson (c. 1024 – 25 October 1047), better known as Magnus the Good, is the King of Norway from 1035 and King of Denmark from 1042, ruling over both countries until his death in 1047.

He is an illegitimate son of Olaf II of Norway, but flees with his mother when his father is dethroned in 1028.

He returnesto Norway in 1035 and is crowned king at the age of 11.

In 1042, he is also crowned king of Denmark.

Magnus rules the two countries until 1047, when he dies under unclear circumstances.

After his death, his kingdom is split between Harald Hardrada in Norway and Sweyn Estridsson in Denmark.