The Temple of Hercules Victor or Hercules Olivarius is a Roman temple in Piazza Bocca della Verità, the former Forum Boarium, in Rome, Italy. It is a tholos, a round temple of Greek 'peripteral' design completely surrounded by a colonnade. This layout caused it to be mistaken for a temple of Vesta until it was correctly identified by Napoleon's Prefect of Rome, Camille de Tournon.

Ancient Roman temples were among the most important buildings in Roman culture, and some of the richest buildings in Roman architecture, though only a few survive in any sort of complete state. Today they remain "the most obvious symbol of Roman architecture". Their construction and maintenance was a major part of ancient Roman religion, and all towns of any importance had at least one main temple, as well as smaller shrines. The main room (cella) housed the cult image of the deity to whom the temple was dedicated, and often a table for supplementary offerings or libations and a small altar for incense. Behind the cella was a room, or rooms, used by temple attendants for storage of equipment and offerings. The ordinary worshiper rarely entered the cella, and most public ceremonies were performed outside of the cella where the sacrificial altar was located, on the portico, with a crowd gathered in the temple precinct.