Paestum is the classical Roman name of a major Graeco-Roman city in the Campania region of Italy. It is located in the north of Cilento, near the coast about 85 km SE of Naples in the province of Salerno, and belongs to the commune of Capaccio, officially also named Capaccio-Paestum.

Paestum is situated close to the Tyrrhenian coast on the road linking Agropoli to Battipaglia. Its population is mainly located in the quarters surrounding the ancient Graeco-Roman ruins, as Santa Venere (to the south, near the hamlet of Licinella), Andreoli (north) and Torre di Paestum (west, by the sea). The town also has a railway station on the Naples-Salerno-Reggio Calabria line.

Founded around the end of the 7th century BC by colonists from the Greek city of Sybaris, and originally known as Poseidonia. Outside of archaeological evidence very little is known about Paestum during its first centuries. Archaeological evidence indicates that the city was expanding with the building of roads, temples and other features of a growing city. Coinage, architecture and molded votive figurines all attest to close relations maintained with Metaponto in the sixth and fifth centuries. It is not until the end of the fifth century BC that the city is mentioned, when according to Strabo the city was conquered by the Lucani. From the archaeological evidence it appears that the two cultures, Greek and Oscan, were able to thrive alongside one another. What is known is it later became the Roman city of Paestum in 273 BC after the Graeco-Italian Poseidonians sided with the loser, Pyrrhus, in war against Rome during the first quarter of the third century BC.