John J. Koepsell (September 26, 1853 – March 11, 1925) was an American businessman and politician.
Born in Milwaukee, Wisconsin, Koepsell was in the hardware business.
He also served as an assistant factory inspector during the administration of Wisconsin Governor Robert La Follette, Sr. Koepsell served on the school board and was the board president.
In 1917, Koepsell served in the Wisconsin State Assembly and was a Republican.
This article about a Republican Party member of the Wisconsin State Assembly born in the 1850s is a stub.