Medzhybizh (Ukrainian: Меджибіж; Polish: Międzybóż; German: Medschybisch; Yiddish: מעזשביזש, romanized: Mezhbizh), formerly Mezhybozhe, is a rural settlement in Khmelnytskyi Oblast, western Ukraine. It is located in Khmelnytskyi Raion, 25 kilometres from Khmelnytskyi on the main highway between Khmelnytskyi and Vinnytsia at the confluence of the Southern Buh and Buzhok rivers. Medzhybizh was once a prominent town in the former Podolia Province. Its name is derived from "mezhbuzhye", which means "between the Buzhenka (and the Buh) Rivers". It is known as the birthplace of the Jewish Hasidic mystical religious movement. Medzhybizh hosts the administration of Medzhybizh settlement hromada, one of the hromadas of Ukraine. Current population: 1,237 (2022 estimate); 1,731, (2001 census).

Medzhybizh is first mentioned in chronicles as an estate in Kievan Rus. It was given to Prince Svyatoslav by the prince of Kyiv in the year 1146. In 1148, ownership transferred to Rostyslav, the son of Yuri Dolgoruky. The wooden fortress that stood there was destroyed in 1255. After the Mongol incursion, by 1360, the town and surrounding territory passed into the hands of the Lithuanians. The town suffered from numerous attacks by the Tatars in 1453, 1506, 1516, 1546, 1558, 1566, and 1615. In 1444 the town was incorporated into lands administered by Poland. In the 16th century, the territory was controlled by the Sieniawski and Potocki Polish noble families. In 1511 work began to replace the wooden palisades with massive stone fortifications, many of which can still be seen today. A dam was built across the Southern Bug river to provide a defensive lake, and a rhomboid Medzhybizh Castle with four towers was built. The state-of-the-art fortifications made Medzhybizh one of the strongest military sites in the region and led to the rise of its prosperity in the next three centuries. - In 1571 a census was recorded, listing the population as being made up of 95 Ruthenians, 35 Jews, and 30 Poles. In 1593 Adam Sienawski gave the town Magdeburg rights.

In the mid-16th century the Zasławski family, a Polish noble family, turned Medzhybizh into an impregnable fortress. The Zaslavskys used Medzhybizh as their base from which to defend the southern borders from the incursions of the Ottoman Turks and Crimean Tatars.

In 1648, the cossack uprising led by Bohdan Khmelnytsky captured the town three times and held the region for the period of one year. At the time, there were approximately 12,000 residents living in Medzhybizh and its environs. Of this number there were 2500 Jews living in Medzhibozh in the year 1648 out of a total Jewish population of Podolia of 4000 souls (spread between 18 communities). The massacre of the Jews by the Cossacks under the command of Danylo Nechay and Maksym Kryvonis occurred on July 20, 1648 in Medzhybizh; almost all 2500 Jews were either killed or taken into captivity. The Jewish population in Medzhybizh was virtually eradicated, and there were no burials recorded for several years after 1648, consistent with depopulation. As late as 1661, only a handful of Jews remained in Medzhybizh. In the 1678 census their numbers had reportedly increased to 275 residents.

Jan Casimir and Khmelnitsky negotiated a treaty in 1649, however, the hostilities continued into 1651 and 1653. In 1657, the Hungarian Prince Rákóczi took the city, eventually ceding it to the Turks in 1672. It remained under Turkish administration until 1682.

Weakened by the Cossack uprising, Podolia was invaded and occupied by Turkey in 1672. Medzhybizh became part of the Turkish Eyalet of Kamieniecki as "Mejibuji" and was a sanjak center with nahiyas of Mejibuji, Poloskiruf, Çornosturuf and Konstantın.

In 1682, Medzhybizh was recaptured by the Poles under Jan Sobieski. However, they did not regain full control until 1699 because the town was frequently ravaged by ongoing struggles with the Turks.

After Medzhybizh was recaptured from the Turks, it went through what many consider its golden age during the 17th and 18th centuries. Under the Sieniawski family and later the Czartoryski family, the town prospered. Medzhybizh successfully defended itself from several Haidamak attacks. By the mid-18th century, Medzhybizh was the seat of power in Podilia Province. It had a population of nearly 5,000, of which there were 2,500 Jews.