Saint-Martory was inhabited since prehistoric times. The caves of Tourasse, Azilian, and that the shelter Montconfort, the Reindeer Age, testifies. The village was besieged in 72 BC C. by Pompey. At these times, the village was called Calagurris. In the 11th century. and the 18th century., the city is under the control of the lords of Montpezat and counts of Comminges. In 1790, the village became capital of the canton and in 1794 took the name of Mountain Garonne. In the mid-19th century., Thanks to the Garonne, Saint-Martory experienced a boom period with the business paper. Its present name comes from a saint called "Martiry".