Opiter (/ˈoʊpɪtər/ or /ˈɒpɪtər/) is a Latin praenomen, or personal name, which was used primarily during the early centuries of the Roman Republic. It is not usually abbreviated, but is sometimes found with the abbreviation Opet., apparently based on an archaic spelling of the name. No examples of a feminine form used as a praenomen are known, but from a cognomen it appears to be Opita. The name gave rise to the patronymic gens Opiternia, and perhaps also gens Opetreia.