La Ruinette is a mountain of the Swiss Pennine Alps, overlooking the Lake of Mauvoisin in the canton of Valais. With an altitude of 3,875 metres above sea level, it is the highest summit between the Grand Combin and the Dent Blanche. La Ruinette lies close to the better known Mont Blanc de Cheilon which has almost the same height (3,870 m).