| Laomedeia | |
| Alt Names: | S/2002 N 3 |
| Discovered: | August 13, 2002 |
| Adjective: | Laomedeian[1] |
| Mpc Name: | Neptune XII |
| Named After: | Λαομέδεια Lāomedeia |
| Satellite Of: | Neptune |
| Group: | Sao group |
| Epoch: | 2003 Jun. 10.00 TT |
| Semimajor: | 23,613,000 km |
| Eccentricity: | 0.3969 |
| Inclination: | 37.874° |
| Period: | 3171.33 days (8.68 yr) |
| Mean Diameter: | 42 km |
| Albedo: | 0.04 |
Laomedeia, 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. 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). It is named after Laomedeia, one of the 50 Nereids.