Jon P. Wilcox (born September 5, 1936) is an American lawyer and retired judge. He was a justice of the Wisconsin Supreme Court for 15 years, appointed by Governor Tommy G. Thompson in 1992 and leaving office in 2007. Prior to his time on the Supreme Court, he served for 13 years as a Wisconsin Circuit Court Judge, including seven years as Chief Judge of the 6th Judicial Administrative District of Wisconsin Circuit Courts. Earlier, he represented Green Lake and Waushara counties in the Wisconsin State Assembly as a Republican.