Ladislaus V, more commonly known as Ladislaus the Posthumous, was Duke of Austria and King of Hungary, Croatia and Bohemia. He was the posthumous son of Albert of Habsburg with Elizabeth of Luxembourg. Albert had bequeathed all his realms to his future son on his deathbed, but only the estates of Austria accepted his last will. Fearing an Ottoman invasion, the majority of the Hungarian lords and prelates offered the crown to Vladislaus III of Poland. The Hussite noblemen and towns of Bohemia did not acknowledge the hereditary right of Albert's descendants to the throne, but also did not elect a new king.

The King of Hungary was the ruling head of state of the Kingdom of Hungary from 1000 to 1918. The style of title "Apostolic King of Hungary" was endorsed by Pope Clement XIII in 1758 and used afterwards by all monarchs of Hungary.