Oderzo (Latin: Opitergium; Venetian: Oderso) is a comune, with a population of 20,003,[3] in the province of Treviso, in the Italian region of Veneto.

The centro storico, or town center, is rich with archeological ruins which give insight into Oderzo's history as a notable crossroad in the Roman Empire.

Starting from the north and then proceeding clockwise, they are: The earliest settlement of the area can be dated to the Iron Age, around the 10th century BC.

Citizens of Oderzo likely were involved in the Social War in 89 BC since acorn-like missiles with names in Venetic and Latin inscriptions have been found at Ascoli Piceno.

[5] During the Roman Civil War, Caius Volteius Capito, a centurion born in Oderzo, led a number of men from the town to fight on the side of Julius Caesar against Pompey.

A number of Roman authors mention the city, among whom are Claudius Ptolomeus, Strabo,[8] Pliny the Elder,[9] Lucan,[10] Tacitus,[11] Livy and Quintilian.

[12] By the 5th century, Oderzo shared the fate of the rest of Venetia and had to deal with attacks in 403 by the Visigoths led by Alaric, in 452 by the Huns whose leader, Attila, according to a local legend hid a treasure in a town's pit, in 465 during a revolt of Visigothic and Roman soldiers who objected to the rule of Severus and in 473 by the Ostrogoths who took control of Rome and all of Italy after 476.

The Lombard king, Rothari, subsequently led a war of vendetta and, having breached Oderzo's defenses, inflicted upon it severe devastation.

In that year, Lombard king, Grimoald I, still holding a grudge for the murder of Taso and Cacco, laid siege to Oderzo.