John Arnan Warner[1] (born January 22, 1943) is an American attorney and judge who served as an associate justice of the Montana Supreme Court.
He attended Montana State University in Missoula, from which he earned a Bachelor of Arts in history and political science in 1965.
He held numerous legal positions during this time, including chairman of the Montana Supreme Court's Commission on Uniform District Court Rules, trustee and president of the State Bar of Montana, and Havre City Attorney.
In May 2003, he was appointed to the Montana Supreme Court by Governor Judy Martz to replace the resigning Justice Terry N. Trieweiler.
He retired from the court in 2009 and his position was filled by the appointment of Mike Wheat.