John Hardgrove (June 24, 1836 – December 18, 1928) was a member of the Wisconsin State Assembly.
On December 8, 1862, Hardgrove married Catherine Heraty in Fond du Lac, Wisconsin. They had twelve children before divorcing in 1897. Following the divorce, Hardgrove moved to Hopkins, Minnesota in 1901. He died on December 18, 1928 in Minneapolis, Minnesota.
Hardgrove was a member of the Assembly in 1883, where he served on the Insurance, Banks, and Banking committee. Additionally, he was Superintendent of Schools and Clerk of Forest. He was a Democrat.