The town of Saint-Bonnet-Tronçais is located in the western part of the department of Allier, in limit of the Cher: the two nearest towns are Montluçon (Allier) at 42 km and Saint-Amand-Montrond (Cher) at 20 km. The village of Saint-Bonnet-Tronçais has developed on the edge of the forest of Tronçais near the Sologne river and the natural pond of Saint Bonnet (45 hectares), a popular tourist site.
From the Gallo-Roman era, the city is a crossroads between the path connecting Avaricum (Bourges) to Gergovie (Lyon) and the path from Bourbon to Drevant (south of the expensive). The water of the ponds, with the forest and the ore, are at the origin of the rise of Saint-Bonnet-Tronçais. The commune bears this name since 1893. Previously it was called Saint-Bonnet the desert.