Adolphus Frederic St. Sure (March 9, 1869 – February 5, 1949) was an American judge. He served as a United States District Judge for the United States District Court for the Northern District of California for 22 years, until June 30, 1947.
St. Sure was the grandson of Adolph Fredrik St. Sure Von Lindsfelt, a physician, sometimes spelled "Adolf Frederik Saint Sure" or "Lindsfeldt", who was a former Swedish Army officer and Chamberlain to the Court of King Charles XIV John (Karl XIV Johan) and fled Sweden to avoid the judgment of a bankruptcy Court. He adopted the name "St. Cyr", later anglicized to "St. Sure". Lindsfelt came to America as an early settler of the Pine Lake Settlement known as "Nya Upsala" (New Upsala), in Wisconsin, founded by Gustaf Unonius. Lindsfelt later studied at Rush Medical College in Chicago and became a medical doctor and a Civil War surgeon in the Union’s 15th Wisconsin Volunteer Regiment.
Born in Sheboygan, Wisconsin, St. Sure moved to California with his parents, Franklin Adolph St. Sure and Ellen Donohue St. Sure, when six months old. St. Sure’s father was a merchant and Confederate veteran who settled his family in Oroville, California, where he ran a shop as a druggist catering to the area gold dredging miners. St. Sure’s uncle, Charles Washington St. Sure, settled in Oroville as well. St. Sure was thrown into the role as head of the family when his father died in a mysterious drowning. He quit school at 13 to help his mother support the family. His first job was as a printer's devil at the Oroville Mercury. St. Sure moved to Alameda, California, in 1891. He later worked as a reporter at the San Francisco Examiner, and the San Francisco Chronicle.