Joseph Trotter Mills (December 18, 1812 – November 22, 1897) was an American attorney, jurist, Republican politician, and Wisconsin pioneer.

Born in 1812 in Cane Ridge, Kentucky,[1] near Paris, Joseph Trotter Mills as a youth lived and studied with his uncle Benjamin Mills, who was a judge of the Kentucky Court of Appeals.

He worked as a tutor in 1834 and 1835, teaching the children of Colonel Zachary Taylor,[1] then commanding officer of Fort Crawford, Prairie du Chien, Michigan Territory.

He prepared to change his work by reading the law with an established firm; in 1844, he was admitted to the Wisconsin bar.

From 1865 to 1877, Mills served as Wisconsin Circuit Court judge.