Medzhybizh Fortress, Medieval fortress in Medzhybizh, Ukraine.

Medzhybizh Fortress is a stone castle on a triangular promontory between the Southern Bug and Buzhok rivers. Its courtyard measures 130 m long and 85 m wide, enclosed by walls up to 4 m thick and 17 m high, with corner towers projecting beyond the wall line. Inside are a 16th-century palace, the Church of Saint Nicholas, and a five-sided Knight's Tower.

The fortress was first recorded in 1146 and transformed from a wooden structure into a stone fortification during the 14th century while under Lithuanian rule. This conversion reflected the military reinforcement of the region during that era.

The fortress grounds include Saint Stanislaw church, which transitioned between chapel, mosque, and Orthodox church depending on who controlled the region. These changes show how the place adapted to different communities and their beliefs.

The site is best reached by public transport or taxi from the nearby city of Khmelnytskyi. Wear sturdy shoes for uneven ground and be ready for changing weather conditions.

The castle has been a full member of the European cultural route FORTE CULTURA since April 2022, when the status was granted at the annual conference in Terezín; it had been an associate member since 2020. In 2017 Ukrposhta issued a stamp showing the fortress, and in 2018 the National Bank of Ukraine released 5-hryvnia and 10-hryvnia commemorative coins named after it.