The Battle of Hatteras Inlet Batteries was the first combined operation of the Union Army and Navy in the American Civil War, resulting in Union domination of the strategically important North Carolina Sounds.

The Union Navy was the United States Navy (USN) during the American Civil War, when it fought the Confederate States Navy (CSN). The term is sometimes used carelessly to include vessels of war used on the rivers of the interior while they were under the control of the United States Army, also called the Union Army.