C.S. Army Tug Neptune (circa 1862-1863) was a wooden tugboat taken over by the Confederate Army in about 1862 for the Texas Marine Department. She was employed as a tug, transport and lookout vessel in the vicinity of Galveston.
On 1 January 1863, during the Battle of Galveston, Confederate troops used her and the gunboat Bayou City in an effort to board and capture the USS Harriet Lane. Though the enterprise was a success, the Neptune was badly damaged and sank shortly afterwards.