Laomedeia /ˌleɪəməˈdiːə/, also known as Neptune XII, is a prograde irregular satellite of Neptune.

It was discovered by Matthew J. Holman, et al. on August 13, 2002.

[6] Before the announcement of its name on February 3, 2007 (IAUC 8802), it was known as S/2002 N 3.

It orbits Neptune at a distance of about 23,571,000 km and is about 42 kilometers in diameter (assuming albedo of 0.04).

[5] It is named after Laomedeia, one of the 50 Nereids.