Gerrit Tunis Thorn (July 20, 1835 – February 3, 1900) was an American lawyer and politician. Born in La Fayette, Onondaga County, New York, Thorn was educated in the La Fayette Public School and at Yates Polytechnic Institute. He studied law in Jamesville, New York and in Pennsylvania. In 1854, Thorn moved to Watertown, Wisconsin and studied law. In 1859 he was admitted to the Wisconsin bar, and he practiced law in Jefferson, Wisconsin. Thorn served in the 29th Wisconsin Volunteer Infantry Regiment in 1862 and had to resign because of ill health. Thorn was the editor of the Jefferson Banner newspaper. He also served as president of the village of Jefferson, Wisconsin. In 1867 and 1868, Thorn served in the Wisconsin State Senate and was a Democrat. In 1869, he moved to Fond du Lac, Wisconsi