Udbina Castle (Croatian: Utvrda Udbina) is a ruined medieval fortified structure in the town of Udbina, Lika-Senj County, Croatia. Built on the top of a hill at the northern end of the town, it overlooks a large part of the Krbava field, just above the place where the fierce and bloody Battle of Krbava between the army of the Kingdom of Croatia and the Ottoman Empire was fought in 1493. Once property of the powerful Kurjaković noble family, the castle was captured by the Ottomans in 1527. It was recaptured in 1689 by Habsburg-Croatian army, but later, by the end of the 19th century, uncared-for, the castle slowly turned into a ruin.