For the supernatural beings in Slavic folklore, see supernatural beings in Slavic folklore.
Willi is a given name. Notable people with the given name include:
Willi Apel (1893-1988), German-American musicologist,
Willi Weber, manager of German racing drivers,
Willi Stoph (1914-1999), East German politician,
Willi Forst (1903-1980), Austrian actor, screenwriter, film,
Willi Hennig (1913-1976), German biologist,
Willi Münzenberg (1889-1940), Communist political activist