The first USS Miantonomoh was the lead ship of her class of four ironclad monitors built for the United States Navy during the American Civil War. Completed after the war ended in May 1865, the ship made one cruise off the East Coast before she began a voyage across the North Atlantic in May 1866 to conduct a lengthy showing the flag mission in Europe. Miantonomoh was decommissioned upon her return in 1867, but was reactivated two years later and assigned to the North Atlantic Squadron before decommissioning again in 1870. The monitor was sold for scrap three years later as part of a scheme where the Navy Department evaded the Congressional refusal to order new ships by claiming that the Civil War-era ship was being repaired while building a new monitor of the same name.

The Miantonomoh class consisted of four monitors built for the Union Navy during the U.S. Civil War, but only one ship was completed early enough to participate in the war. They were broken up in 1874–1875.