The Zaraysk Kremlin is a rectangular fortified citadel, built at the behest of Vasili III of Moscow between 1528 and 1531. The town of Zaraysk is located between Moscow and Ryazan.

A kremlin is a major fortified central complex found in historic Russian cities. The word is often used to refer to the Moscow Kremlin and - metonymically - to the government based there. Other such fortresses are called detinets, such as the Novgorod Detinets.