The Kamianets-Podilskyi Castle (Ukrainian: Кам'янець-Подільська фортеця, romanized: Kamianets-Podilska fortetsia; Polish: twierdza w Kamieńcu Podolskim; Lithuanian: Podolės Kameneco tvirtovė) is a former Ruthenian-Lithuanian castle and a later three-part Polish fortress located in the historic city of Kamianets-Podilskyi, Ukraine, in the historic region of Podilia in the western part of the country. Its name is attributed to the root word 'kamin', from the Slavic word for 'stone'.
Historical accounts date Kamianets-Podilskyi Castle to the early 14th century, although recent archaeological evidence has proved human existence in the area back to the 12th or 13th century. Initially built to protect the bridge connecting the city with the mainland, the castle sits on top of a peninsula carved out by the winding Smotrych River, forming a natural defense system for Kamianets-Podilskyi's historic Old Town neighborhood.