Bionaz (; Valdôtain: ; from 1939 to 1946) is a comune sparso which extends over 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 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: