Nomos (plural: Nomoi) can refer to:
the subdivisions of Ancient Egypt, see Nome
the prefectures of Greece, the administrative division immediately below the peripheries of Greece ()
law (). It is the origin of the suffix -onomy, as in astronomy, economy, or taxonomy. See also Biblical law in Christianity
the spirit of law, in Greek mythology
meaningful orders or worldviews of individuals, in Peter L. Berger's sociology of religion
Studies in Spontaneous Order a magazine published in the 1980s and 1990s, connected with the libertarian movement.
Nomos Publishers (, ).
a German watch company
an American Radiation Oncology company 
a Swiss numismatic firm