Homosexuality in ancient Rome often differs markedly from the contemporary West. Latin lacks words that would precisely translate "homosexual" and "heterosexual". The primary dichotomy of ancient Roman sexuality was active / dominant / masculine and passive / submissive / feminine. Roman society was patriarchal, and the freeborn male citizen possessed political liberty (libertas) and the right to rule both himself and his household (familia). "Virtue" (virtus) was seen as an active quality through which a man (vir) defined himself. The conquest mentality and "cult of virility" shaped same-sex relations. Roman men were free to enjoy sex with other males without a perceived loss of masculinity or social status as long as they took the dominant or penetrative role. Acceptable male partners were slaves and former slaves, prostitutes, and entertainers, whose lifestyle placed them in the nebulous social realm of infamia, so they were excluded from the normal protections accorded to a citizen even if they were technically free. Freeborn male minors were off limits at certain periods in Rome.

In classical antiquity, writers such as Herodotus, Plato, Xenophon, Athenaeus and many others explored aspects of homosexuality in Greek society. The most widespread and socially significant form of same-sex sexual relations in ancient Greece amongst elite circles was between adult men and pubescent or adolescent boys, known as pederasty. Certain city-states allowed it while others were ambiguous or prohibited it. Though sexual relationships between adult men did exist, it is possible at least one member of each of these relationships flouted social conventions by assuming a passive sexual role according to Kenneth Dover, though this has been questioned by recent scholars. It is unclear how such relations between same-sex partners were regarded in the general society, especially for women, but examples do exist as far back as the time of Sappho.