Sigismund of Luxemburg KG (14 February 1368 – 9 December 1437) is King of Hungary, of Croatia from 1387, of Bohemia from 1419, and Holy Roman Emperor for four years from 1433 until 1437, the last Emperor of the House of Luxemburg.

He is also King of Italy from 1431, and of Germany from 1411.

Sigismund is one of the driving forces behind the Council of Constance that ends the Papal Schism, but which in the end also leads to the Hussite Wars that dominate the later period of Sigismund's life.

He is buried in Nagyvárad, Kingdom of Hungary (now Oradea, Romania) next to the tomb of the King Saint Ladislaus I of Hungary.