thumb|Ascent of Mont Blanc, showing route from Plan Glacier to Durier Hut, over Aiguille de Bionnassay, Dome du Gouter, Bosses ridge to Mont Blanc summit. Return route via Le Goûter is shown in blue.
The Aiguille de Bionnassay (; elevation ) is a mountain in the Mont Blanc massif of the Alps in France and Italy. It has been described as "one of the most attractive satellite peaks of Mont Blanc", and is located on its western side.
The Glacier de Miage – not to be confused with the much larger Glacier du Miage on the Italian side (see above) – forms from snows collecting between the Aiguille de Tricot and the south-western face of the Aiguille de Bionnassay. The glacier descends in a south-westerly direction for approximately 2.5 km.
The east ridge was first climbed in descent as part of a traverse from the Dômes de Miage by Katharine Richardson, Emile Rey and Jean-Baptiste Bich on 13 August 1888.
The first winter ascent of the Aiguille de Bionnassay was made on 20 March 1929 by A. Charlet, F. Frison Roche, H. Hoerlin, E.Schneider and H. Schroeder.
- East Ridge: Described as "a superb snow crest which is often precarious and delicate due to large cornices", the east ridge descends from the summit as an exposed and delicate knife-edge crest to the col de Bionnassay. It is graded AD and can be reached from a traverse of the Bionnassay, or from the Gonella Hut.