Sigrid Undset (May 20, 1882 - June 10, 1949) was a Norwegian novelist and winner of the Nobel Prize in literature for 1928.
Undset was born in Kalundborg, Denmark, but her family moved to Norway when she was 2 years old. In 1924, she converted to Catholicism. She fled Norway for the United States in 1940 because of her opposition to Nazism, but returned after the war in 1945.
Her best-known work in English is Kristin Lavransdatter, a monumental trilogy about life in Scandinavia in the middle ages, published 1920-1922.