Altinum was an ancient town of the Veneti 15 km southeast of modern Treviso, close to the mainland shore of the Lagoon of Venice. It was also close to the mouths of the rivers Dese, Zero and Sile. A flourishing port and trading centre during the Roman period, it was destroyed by Attila the Hun in 452. The town recovered, but was later abandoned when sea-borne sand began to cover it over. Its inhabitants moved to Torcello and other islands of the northern part of the lagoon.

The Veneti were an Indo-European people who inhabited northeastern Italy, in an area corresponding to the modern-day region of Veneto, from the middle of the 2nd millennium BC and developing their own original civilization along the 1st millennium BC.