The Battle of Nicopolis takes place on September 25, 1396 and results in the rout of an allied crusader army of Hungarian, Bulgarian, Croatian, Wallachian, French, Burgundian, German and assorted troops (assisted by the Venetian navy) at the hands of an Ottoman force, raising of the siege of the Danubian fortress of Nicopolis and leading to the end of the Second Bulgarian Empire.

It is often referred to as the Crusade of Nicopolis as it is one of the last large-scale Crusades of the Middle Ages, together with the Crusade of Varna in 1443–1444.