The Aiguille de Bionnassay 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 mountain's south and east ridges form the frontier between the two countries, and its summit is a knife-edge crest of snow and ice. Reaching it via any route provides a "splendid and serious snow and ice climb".