Apparently his father was a burgher there. His early schooling came at the cathedral school at Västeras. A lifelong love of travel was ignited when at age fifteen he made a trip to Oslo. Three Magnus brothers, Hans, Olaf and Per (Latinized as Johannes, Olaus and Petrus) became priests. From age twenty to twenty-seven Olaus studied in the German universities of Rostock and Greifswald; no doubt this was the period when he studied the 1482 printing of Ptolemy’s Geographia. He received a BA degree from the University of Rostock, probably in 1513 (Karrow 1993, 363).

Olaus gave up a position in Uppsala in 1518 to become a seller of indulgences in the north of Scandinavia. In his book, he writes that he asked to be sent to fight Lutheranism in northern Sweden, Finland and northwestern Norway. He may have visited the Lofoten Islands at this time. While on these journeys, he began to gather the information for his map and book. He was good at drawing, and it is believed that he drew many illustrations that appeared in them.