The gens Oppia was an ancient Roman family, known from the first century of the Republic down to imperial times.
The gens may originally have been patrician, as they supplied priestesses to the College of Vestals at a very early date, but all of the Oppii known to history were plebeians.
[1] The Oppii were probably Sabines, one of the peoples who made up a significant portion of the early Roman populace.
The nomen Oppius is classed by Chase among a number of gentilicia that were not Latin, but came from among the various neighboring regions, in this case that of the Sabines.
[2] The earliest Oppii to appear in history used the praenomina Spurius, Marcus, and Gaius.