Wormius was the son of the mayor of Aarhus, and apparently a rich man's son. He came from a Lutheran family, and his mother was a refugee from religious persecution in the Netherlands. He was something of a perpetual student; he began his college education at the University of Marburg in 1605, and received his Doctor of Medicine degree from the University of Basel in 1611, and a Master of Arts degree from the University of Copenhagen in 1617. The rest of his academic career was spent in Copenhagen, where he taught Latin, Greek, physics, and medicine. He was personal physician to King Christian V of Denmark. Somewhat remarkable for a physician of the time, he remained in the city of Copenhagen to minister to the sick during an epidemic of bubonic plague.
Wormius is better known as a collector of early literature in the Scandinavian languages. He also wrote a number of treatises on runestones and collected texts that were written in that alphabet. The King of Denmark underwrote Wormius's runic researches and gave him letters of introduction to the bishops of Denmark and Norway to let them know that he was making his collections with royal approval. In 1626 Wormius published his Fasti Danici, or "Danish Chronology," containing the results of his researches into runic lore; and in 1636 he followed this up with Runir seu Danica literatura antiquissima, "Runes: the oldest Danish literature," a compilation of transcribed runic texts.
The genuine contributions to learning made by Olaus Wormius have in more recent years been supplanted by a fictional character given his name. H. P. Lovecraft mentioned him as a translator into Latin of his notorious fictional grimoire, the Necronomicon. Lovecraft also turns him into a Dominican priest, and misplaces him in the thirteenth century.