Neptune has 13 known moons. Four of which have been discovered and yet unamed since 2004. Nine of the 13 moons are named moons. Here is a alphabetical list:
| Despina | A moon of Neptune was discovered by the Voyager Imaging Team on August 2, 1989. Despina is also designated as "Neptune V" and "S/1989 N3". In Greek mythology, Despina was a nymph who was a daughter of Poseidon. |
| Galatea | A moon of Neptune was discovered by the Voyager Imaging Team in July 1989. Galatea is also designated as "Neptune VI" and "S/1989 N4". In Greek mythology, Galatea was one of the Nereids. |
| Larissa | A moon of Neptune was discovered by Harold J. Reitsema, William B. Hubbard, Larry A. Lebofsky and David J. Tholen on May 24, 1981. Larissa is also designated as "Neptune VII" and "S/1981 N1". In Greek mythology, Larissa was a nymph who was a lover of Poseidon (Neptune). |
| Naiad | A moon of Neptune was discovered by the Voyager Imaging Team in September, 1989. Naiad is also designated as "Neptune III" and "S/1989 N6". In Greek mythology, the Naiad were a type of nymph who presided over fountains, wells, springs, streams, and brooks, as river gods. |
| Nereid | The smallest moon of Neptune was discovered by Gerard Kuiper in May 1, 1949. Nereid is also designated as "Neptune II". In Greek mythology, the Nereid were sea-nymphs. |
| Proteus | The second-largest, innermost moon of Neptune was discovered by Stephen P. Synnott on June 16, 1989. Proteus is also designated as "Neptune VIII" and "S/19989 N1". In Greek mythology, Proteus was the shape-changing sea god. |
| Psamathe | A moon of Neptune was discovered by Scott S. Sheppard, David C. Jewitt and J. Kleyna in 2003. Psamathe is also designated as "Neptune X" and "S/2003 N1". In Greek mythology, Psamathe was a nereid and was married to king Proteus of Egypt. |
| S/2002 N1 | A moon of Neptune was discovered by Matthew J. Holman and Team in 2002. |
| S/2002 N2 | A moon of Neptune was discovered by Matthew J. Holman and Team in 2002. |
| S/2002 N3 | A moon of Neptune was discovered by Matthew J. Holman and Team in 2002. |
| S/2002 N4 | The outermost moon of Neptune was discovered by Matthew J. Holman, Brett J. Gladman and Team in 2003. |
| Thalassa | A moon of Neptune was discovered by the Voyager Imaging Team in September, 1989. Thalassa is also designated as "Neptune IV" and "S/1989 N5". In Greek mythology, Thalassa was a daughter of Aether and Hemera. |
| Triton | The largest moon of Neptune was discovered by William Lassell on October 10, 1846. Triton is also designated as "Neptune I". In Greek mythology, Triton was a sea god and the son of Neptune. |
