Pierce Butler (March 17, 1866-November 16, 1939) was an American jurist who served as an Associate Justice of the United States Supreme Court from 1923 until his death in 1939.

Born in Pine Bend, Minnesota , he was a graduate of Carleton College. Admitted to the bar in 1888, he served as state's attorney in Ramsey County, Minnesota before entering private practice in St. Paul, Minnesota where he did much railroad work for James J. Hill and others. Though much admired by Chief Justice William Howard Taft, Butler's attacks on "radical" professors at the University of Minnesota (where Butler served as a Regent) made him a controversial nominee when proposed by Warren Harding. Senator Henrik Shipstead of his home state vigorously opposed him, as did labor and progressive groups. However, with the support of Catholic and business groups, he was confirmed by an overwhelming vote and took office January 2, 1923.

While on the Court, he vigorously opposed regulation of business and the provision of welfare by the government. He voted against every one of Franklin Roosevelt's New Deal laws that came before the Court earning a place amongst the Four Horsemen that also included James Clark McReynolds, George Sutherland, and Willis Van Devanter. He died in Washington, D.C. while still a justice and is buried in the Calvary Cemetery in St. Paul.