The Buthier is a mountain torrent in north-west Italy. A left bank tributary of the Dora Baltea, its entire course lies within the Valpelline, a valley in the region of Aosta Valley.

One branch of the river is formed by the Tsa de Tsan Glacier at an elevation of about 2,700 metres (8,900 ft); a second by the Grandes Murailles glacier at about 3,000 metres (9,800 ft). The river is then dammed to form the Place-Moulin Lake reservoir, after which it passes through the communes of Bionaz, Oyace, Valpelline, Roisan and finally Aosta where it joins the Dora Baltea.

The principal tributaries from the left are:

• Rû Verdonaz
• Vessonaz;

and from the right:

• Ollomont
• Artanavaz.

• Pont de Pierre, a Roman bridge from the time of Augustus (r. 30 BC –14 AD)

This article began as a translation from its counterpart in the Italian Wikipedia, specifically from this version