The Siege of Zhvanets (Ukrainian: Облога Жванця, Polish: Oblężenie Żwańca; September – 15 December, 1653) was fought between the Cossack Hetmanate, Crimean Khanate and the Polish–Lithuanian Commonwealth as a part of the Khmelnytskyi Uprising.

When news of this reached King Jan Kazimierz Waza, he decided to abandon his positions in Bar, Ukraine, and head towards Zhvanets, to await Moldavian and Transilvanian reinforcements.

Polish forces camped at the confluence of the Zhvanchyk [de] and the Dniestr rivers, building a pontoon bridge over the Dniester, to keep in touch with Bucovina.

As time went by and the weather worsened, Polish defenders began to starve, and a number of soldiers fled their positions in search of food.

The situation was anxiously observed by Khan Islam III Giray, who did not wish for complete destruction of Polish forces, as this would eventually strengthen the Cossacks, who, despite the temporary alliance, were his traditional enemies.