Bionaz (French: [bjɔna] ⓘ; Valdôtain: Bioun-a; Biona from 1939 to 1946) is a comune sparso[3] which extends over 143 square kilometres (55 sq mi) of the North-Eastern Valpelline area of the Aosta Valley region of northwest Italy.

The population of about 240 is dispersed among 20 or more small alpine villages and hamlets including Plan-de-Veyne, which is the main centre and the capoluogo (locally and officially also chef-lieu, in French).

The commune belongs to the Unité des communes valdôtaines du Grand-Combin.

The commune's statute[4] designates the following frazioni (locally officially called hameaux, in French): The following localities, villages and other places not formally designated as hameaux, are also listed in the statute: Within the boundaries of the commune, there are also three mountain huts:

This article on a location in Aosta Valley is a stub.