Sydoriv (Ukrainian: Сидорів) is a village located on the right bank of the Zbruch River in Chortkiv Raion (district) of Ternopil Oblast (province in western Ukraine).

On April 5, 1547, Polish King Sigismund I the Old granted a privilege to Jakub Potocki to found the town of Sydoriv.

They had three sons, the youngest of whom, Marcin, became a Polish crown hetman and inherited many lands in Podillia after his brothers' deaths: Vinnytsia, Uman, and the family castle in Sydoriv.

Here, in 1640, the hetman ordered a stone castle to be built on the top of an island formed by the rivers Sukhodil and Slobidka (now only ruins remain).

For three years, Jan Samuel Chrzanowski and his wife Anna, who later distinguished herself in the defense of Terebovlia Castle in 1676, were the commandant here.