Zumaglia Castle, Medieval castle in Zumaglia, Italy.

Zumaglia Castle is a medieval fortress located on the summit of Brich di Zumaglia between the municipalities of Zumaglia and Ronco Biellese in the Province of Biella. The structure sits prominently on the hilltop and commands views of the surrounding terrain from its position.

The castle originated in 1291 on the site of earlier fortifications that had occupied the location. It took on its current form through reinforcements undertaken in 1329 under orders from Lombardo della Torre, the Bishop of Vercelli.

Since 2013, a theater association has used this place as a cultural center, organizing regular performances, exhibitions, and concerts. It has become a living hub for artistic activities and community gatherings in the region.

From the Ronco Biellese sports center, paved paths and a dirt road lead up to the castle, with parking available for about 30 cars. The climb is manageable on foot and the routes are generally walkable, though path surfaces vary in quality.

The toponym Zumaglia comes from zumaja, a Biellese word for breast, describing how the Brich and its twin hill Monte Prevè look from a distance. The wooded hilltop also carries trees of rare or exotic species, some of notable size, around the rebuilt castle.