It served as the administrative center of the Koziatyn Raion (district); the city itself was not a part of the district and was separately incorporated as the city of regional significance until 2020, when it was incorporated into Vinnytsia Raion.

Koziatyn became a town of the Berdychiv district of Kyiv Governorate on July 7, 1874.

In April 1920, during the Polish-Bolshevik War, the town was captured by Polish forces in what became known as the Raid on Koziatyn.

During World War II, Koziatyn was under German occupation from 15 July 1941 until 28 December 1943.

In July 2000, the Verkhovna Rada of Ukraine decided to include Koziatyn in the category of cities of regional subordination.