The commune of Chancy was first mentioned in 1260, it had 346 inhabitants in 1850, growing to 913 in 2000.
Roman remains, including a tile factory and a castrum at Montagny, are found in the area. The counts of Geneva exercised seigneurial rights until 1260. After the Reformation in 1536, Chancy became part of Geneva.
The town hall replaced the medieval church in 1905. A bridge replaced ferry transport in 1424 and was rebuilt in 1874.