Medzhybizh Castle, built as a bulwark against Ottoman expansion in the 1540s, became one of the strongest fortresses of the Crown of the Kingdom of Poland in Podolia. It is situated at the confluence of the Southern Bug and Buzhenka rivers, in the town of Medzhybizh, Ukraine. Today the castle is part of the State Historical-Cultural Preserve.
The first wooden fort was built around 1146 by the rulers of Bolokhov. The fort probably survived the Mongol invasion, but was dismantled by Daniel of Galicia in 1254 at the bidding of the Golden Horde. The new fort was built by Koriat's heirs after the Grand Duke of Lithuania had defeated the Golden Horde at the Battle of Blue Waters in 1362.
Podolia passed to the Polish Crown in 1432. The castle was confiscated from the House of Koriat and became the property of the Polish kings. About 1540 the castle was completely rebuilt by its new owner, Mikołaj Sieniawski. The Sieniawski family owned Medzhybizh until its extinction in the early 18th century. The stronghold was reconquered from the Turks in 1699 and passed to the Czartoryski family in 1731.