Eunomia is asteroid #15 and with a diameter of slightly above 230 km one of the largest asteroids in the Asteroid Main Belt. Eunomia was discovered by the Italian astronomer Annibale de Gasparis. Eunomia is a stony asteroid (type S) and head of the Hirayama-family Eunomia.

Eunomia is estimated to contain around one percent of the total mass of the Asteroid Main Belt. This makes also the Eunomia-family the most prominent in the Asteroid Main Belt. The Eunomia-family is the sixth-largest Hirayama-family, consisting of approximately six-thousand members or 1.4 % of the Asteroid Main Belt.

Eunomia (Εὐνομία) is one of the Horai or Horae of Greek mythology. This means that Eunomia (Εὐνομία) is also a daughter of Zeus and Themis. Although different family trees are known for Eunomia too. So could she be a daughter of Aphrodite and Hermes or a daughter of Promatheia, which means of precaution. The names of the Horai differed over time. Eunomia is part of the second generation. Eunomia is the goddess of laws and legislation. Her name means good order. The other Horai of this generation are Dike and Eirene. Without this generation of the Horai can’t stable human societies exist.

Eunomia is in poetry contrasted to Dysnomia, who is the daughter of Eris, after whom asteroid #136199 (the dwarf-planet Eris) is named. The plutoid Eris has a natural satellite, that is named Dysnomia. Because Dysnomia is the goddess of lawlessness, so Eunomia can, perhaps (because Eunomia has roughly a third of the diameter of Dysnomia or a tenth of the diameter of Eris) together with her sisters, be seen as a small counterweight to Eris.