Magnus (died 23 August 1106) was duke of Saxony from 1072 to 1106. Son of Ordulf, Duke of Saxony and Wulfhild, Princess of Norway, he was the last member of the House of Billung. From 1070 on, he was involved in the war between Saxon noblemen and the Salian king Henry IV.

He was married in 1071 with Sofia of Hungary, daughter King Bela I of Hungary and had in this marriage two daughters:
1. Wulfhilde (1075 – 1126), who was married to Duke Henry IX of Bavaria.
2. Eilika (1080 – 16 January 1142), married to Count Otto of Ballenstedt.