The Siege of Kyzyl-yar Fortress occurred in November 1655 when Crimean rebel armies loyal to the deposed Khan Mehmed IV Giray captured Kyzyl-yar Fortress (Melitopol) on the Sea of Azov.
Following the Battle of Trudove and the Battle of Malyi Utlyuh, Mehmed IV's army, consisting of Jerzy Wisniewski's Polish mercenaries and the Tatar rebels of Ahmed-pasha and Bukryn-bey, besieged the fortress of Kyzyl-yar. The fortress' commander Mirza Divey refused to join the rebellion, forcing the rebels to take Kyzyl-yar by storm. On 1 November, the Poles and rebels attacked the walls with ladders, and the ramparts were secured after great slaughter. Some of the worst fighting occurred in the town square, where fighting between the attackers and the garrison left heaps of Tatar bodies scattered in the dirt. Ultimately, the rebels took the fortress with 69 losses, cutting the khanate in half; Azaq-qale (Azov) was isolated from Crimea proper.