Château de Chavagneux, Historical castle in Genouilleux, France.

Château de Chavagneux stands in Genouilleux on the banks of the Saône. Of the 13th-century fortress only the cylindrical brick keep survives, built in the 1290s–1300s and comparable to the keeps of Montellier and Plantay. About a hundred metres away, the Bonna de Perrex family built a second castle in 1774, partly from Savoyard carrons bricks taken from two demolished towers and the old walls. Its west facade gained a pediment in the 1830s.

This castle traces its origins to the 13th century when the initial structure was built. It received recognition as a historical monument from French authorities in 1942.

The name Chavagneux comes from the family of the Vaux, who took it as their own before dying out around 1375. In 1530 the brothers Jean and Antoine de la Porte split the land into Grand-Chavagneux and Petit-Chavagneux, and the two halves were reunited in 1617 when Jean Sajot bought the Petit-Chavagneux. The cylindrical brick keep, built in the 1290s and 1300s, is compared in the sources to the keeps of Montellier and Plantay.

The site is private property and not open for visits; the keep and fortress remains can be seen from the public road. The castle stands on the banks of the Saône in Genouilleux, in the Ain department. The 1942 listing covers only the keep and the remains of the old fortress.

The cylindrical brick keep, built around 1290-1300, is all that remains of the medieval fortress; its form is compared in the sources to the keeps of the castles of Montellier and Plantay. The 1774 second château nearby was partly built with Savoyard carrons (bricks) taken from two demolished towers and the old walls.