The village takes its name from a ninth century bishop, Saint Nonne, who re-evangelized the country after the Norman invasions, and from La Bretesche, a wooden stronghold (breiteiche: big oak tree), the main hamlet at the edge of the Forest of Cruye.

Saint-Nom-la-Bretêche owns a great amount of rich historical buildings.

Saint-Nom-la-Bretêche has updated its graphic identity with a modern symbol of identity based on one of the signs from the old coat of arms : the cinquefoil. This five-leaf grass symbolizes not only the forest of Marly, but also the five districts of the village : Saint-Nom, La Breteche, Valmartin, the Tuilerie and the Vallon.