Napoleon Collins was born in Pennsylvania on 4 March 1814. He became a Midshipman in the United States Navy in January 1834. Promoted to the rank of Lieutenant in 1846, he took an active role in the war with Mexico. During the first years of the Civil War, he commanded several gunboats and attained the rank of Commander in July 1862.

On 7 October 1864, while in command of USS Wachusett, Collins took his ship into a neutral harbor and captured the the Confederate cruiser CSS Florida, towing that ship to sea and taking it to the U.S. Courtmartialled for this illegal undertaking, Commander Collins was sentenced to be dismissed. However, since his seizure of the Florida was both militarily effective and popularly acclaimed in the Northern states, the sentence was not carried out.

Napoleon Collins remained active in the post-war Navy, reaching the ranks of Captain in July 1866 and Rear Admiral in August 1874. On 9 August 1875, while in command of the South Pacific Squadron, he died at Lima, Peru.