The Municipality of Saint-Léonard is located on the right bank of the Rhône, it is spread out on the one hand, on an alluvial plain, formerly marshy, and, on the other hand, on the first slopes of the mountain.

The distribution of municipal territories is very often influenced by rivers. To the south, the Rhône gives it a natural limit, while to the west, the Lienne separates the Communes of St-Léonard and Sion (Uvrier). These two rivers therefore separate the three districts, Sion, Hérens and Sierre.