The first USS Montauk was a single-turreted Passaic-class monitor in the Union Navy during the American Civil War.

The Union ships braved intense fire from Confederates coastal artillery, and kept their own guns operating effectively until withdrawing toward evening.

Damage to the monitors prevented Du Pont from resuming the attack the next day with Montauk taking 20 hits.

Assuming command of the naval forces, John Dahlgren boarded Montauk on July 16 and after consultation with the captains, renewed the attack on Fort Wagner and bombarded it daily until it was evacuated by the Confederates on September 6.

She remained there until sold to Frank Samuel on April 14, 1904, except for a stint from May 1898 to March 1899, when she served with a crew primarily consisting of local naval reservists to protect the harbor of Portland, Maine during the Spanish–American War.