Castello di Marchierù, Medieval castle in Villafranca Piemonte, Italy.

Castello di Marchierù is a castle in Villafranca Piemonte with a main residence, noble chapel, staff quarters, stables, and a farmhouse set within fortified walls. The complex brings together various structures from different periods into a single functioning site.

The castle is first mentioned in 1220 in a document recording a donation of goods to the abbey of Santa Maria di Cavour. Held by the lords of Barge, it passed to Thomas II of Savoy by act of 11 March 1251, then through Thomas III to Philip, founder of the Savoy-Acaia branch. In 1482 it went to the Petitti, cousins of Antonio Bocchiardi, and the following year back to the House of Savoy.

The name Marchierù probably comes from "marcio", meaning well-irrigated, because numerous constant-temperature springs in the area made the land continuously irrigable. Less likely explanations link it to "marchesato", the nearby Marquisate of Saluzzo border, or to the French "macheron", rubble left after Frederick Barbarossa's passage. In 1991 the castle hosted the national council of the Nunziatella military school alumni association, meeting outside Naples for the first time.

The castle is a private historic residence in the Soave hamlet of Villafranca Piemonte, still owned by the Prunas Tola family, so it is not a regularly open monument. Visits depend on the owners' arrangements, and the site lies in the countryside outside the town centre, so reach it by car and confirm access beforehand.

In 1991 the national council of the Nunziatella military school alumni association met in the castle, in the same hall where the Treaty of Cavour was signed, for the first time away from its home seat; the Piedmont-Valle d'Aosta section president, the current owner, hosted it.