Palazzo dei Diavoli, Medieval stone palazzo in Isolotto, Florence, Italy.

Palazzo dei Diavoli is a medieval stone palazzo in Isolotto, Florence, that features sandstone walls and a tower structure typical of early Florentine residential buildings. The construction displays thick masonry and defensive design elements characteristic of tower houses from that era.

The building began as a 13th-century sandstone tower house, later enlarged in the 14th century when other dwellings were built against the tower. From 1427 until the end of the 16th century it belonged to the Florentine Alberti family, who held lands in the suburbs. By the 19th-century land registry it had passed to the Franceschi family and was recorded as a farmhouse with a vegetable garden, a bindolo well and cultivated plots.

The name reflects old local stories about the building's forbidding stone walls and rumors of secret meetings inside. These tales grew from how austere and heavy the structure appears with its thick masonry and defensive tower.

The palazzo is located in the Isolotto neighborhood and can be reached from central Florence by public transportation. The area is easy to navigate, making it straightforward to visit the building during a walk through the district.

Local lore holds that witches gathered inside, or that the devil finished the undecorated building in a single night in exchange for the owner's soul. A rival explanation ties the name to the Alberti family, Ghibellines whom opponents branded "devils"; a third points to the fork at the road's end, forcing a choice like the devil's.