Ornavasso (Ossolano: Urnavass, Walser German: Urnafasch) is a comune (municipality) in the Province of Verbano-Cusio-Ossola in the Italian region Piedmont, located about 110 kilometres (68 mi) northeast of Turin and about 11 kilometres (7 mi) northwest of Verbania.

Ornavasso borders the following municipalities: Anzola d'Ossola, Gravellona Toce, Mergozzo, Premosello Chiovenda.

From the 14th century to the late 19th century, Ornavasso and its frazione of Migiandone were a language island of Walser German, due to the presence of immigrants from the Simplon area.

Traces of the German culture persist in the local dialect and the Carnival tradition.

During World War II, Ornavasso was the base of the Valtoce Partisan Division.