Olaf or Olav (/ˈoʊləf/, /ˈoʊlɑːf/, or British /ˈoʊlæf/; Old Norse: Áleifr, Ólafr, Óleifr, Anleifr) is a Dutch, Polish, Scandinavian and German given name. It is presumably of Proto-Norse origin, reconstructed as *Anu-laibaz, from anu "ancestor, grand-father" and laibaz "heirloom, descendant". Old English forms are attested as Ǣlāf, Anlāf. The corresponding Old Novgorod dialect form is Uleb. A later English form of the name is Olave.
In the Norwegian language, Olav and Olaf are equally common, but Olav is traditionally used when referring to Norwegian royalty. The Swedish form is Olov or Olof, and the Danish form is Oluf. It was borrowed into Old Irish and Scottish Gaelic with the spellings Amlaíb and Amhlaoibh, giving rise to modern version Aulay. The name is Latinized as Olaus.