SS St. Olaf was a Liberty ship built in the United States during World War II. She was named after St. Olaf, the King of Norway from 1015 to 1028. He was posthumously given the title Rex Perpetuus Norvegiae (English: Eternal/Perpetual King of Norway) and canonised at Nidaros, by Bishop Grimkell, one year after his death in the Battle of Stiklestad.