Organized March 20, 1869, was at first called Oxford, but was renamed May 10, 1870, in honor of St. Olaf, born in 995, an early king of Norway, in 1015-30, who consolidated the kingdom and aided the establishment of Christianity, but was killed in a battle with his rebellious subjects, July 29, 1030. He is the patron saint of Norway, and is regarded by its people as the great champion of national independence.
Source: The Book “Minnesota Geographic Names: Their Origin and Historic Significance” Volume 17 – 1920 By Warren Upham”