Avenches (French pronunciation: [avɑ̃ʃ]) is a Swiss municipality in the canton of Vaud, located in the district of Broye -Vully.

The roots of Avenches go back to the Celts. A tribe of Helvetians had built a settlement on the hills of Bois de Châtel, south of the later Roman settlement. Nearby the Helvetii seem to have had their capital on Mont Vully as shown in recent archaeological excavation. The canal-La Broye-which joins Lac Morat to Lac Neuchâtel is thought to be Roman in origin.

The establishment of the Roman settlement of Aventicum , which became the capital of the province, took place around 15-13 B.C. The name comes from the Helvetian spring goddess Aventia.