John Dunne Wickhem (May 25, 1888 – June 19, 1949) was an American lawyer and jurist from Beloit, Wisconsin.

Prior to joining the court, he worked as a professor at the University of Wisconsin Law School.

[1] In 1930, he was appointed to the Wisconsin Supreme Court by Governor Walter J. Kohler Sr., to fill the vacancy caused by the death of Charles H. Crownhart.

[1] His most historically noteworthy opinion on the court was likely State ex rel Martin v. Heil, in which he wrote for a unanimous court that the lieutenant governor-elect would become the next governor following the death of the governor-elect.

[1] On June 18, 1949, he complained of a slight illness after returning from a trip to Evanston, Illinois, and was taken to a hospital in Madison.