John Barnes (July 26, 1859 – January 1, 1919) was an American jurist from Wisconsin.
Born on a farm in Manitowoc County, Wisconsin, Barnes went to Oshkosh Normal School and taught school for six years. He then graduated from University of Wisconsin Law School and practiced law in Manitowoc, Wisconsin and then in Rhinelander, Wisconsin. In 1905, he was appointed to the Wisconsin Railroad Commission. In 1908, he was appointed to the Wisconsin Supreme Court. In 1916, Barnes resigned to become general counsel of Northwestern Mutual Life Insurance.[1][2]