The cave of Mas-d'Azil is a prehistoric cave in the commune of Mas-d'Azil in the department of Ariège, in the center of the French Pyrenees, Occitanie region (formerly in Midi-Pyrénées), in France.

The cavity is crossed by a road and by the river Arize which dug it. It is one of the few caves in the world that can be crossed by car.

It was occupied in different prehistoric and historical times and gave its name to a prehistoric culture, the Azilian.

The cave is first frequented by animals and the inner galleries are rich in woolly mammoth bones, cave bears, and woolly rhinos.

Then prehistoric groups settled there. The cave is known for its many prehistoric remains including the Faon with birds, a very beautiful thruster dated Middle Magdalenian (15,000 to 13,500 years AD) discovered by Marthe and Saint-Just Péquart in 1940, as well as the Coco des roseaux, a hunting scene of the Magdalenian with human figuration rudimentary, engraved on a fragment of animal scapula. It also discovered a button engraved with a female aurochs and her calf on the other side, and a maiden skull, "Magda" (14,000 years old) with two plates of carved bones simulating the eyes in the sockets.

In addition to the richness and diversity of its furniture, the cave also contains several decorated galleries:

• Breuil room: bison, horses, deer, fish, a possible feline, and geometric signs;
• Reindeer Gallery: numerous engravings of animals superimposed;
• Salle du Four: horse hindquarters, ibex head, human face on a natural rocky outline.
• A hard-to-reach casing contains an engraved vulva.

The site gave its name to the Azilian, a prehistoric culture of the Epipaleolithic (about 12,000 to 9,500 BC) between the Magdalenian and Mesolithic defined by Édouard Piette. There is a microlithic industry, flat harpoons, many painted Azilian pebbles (colored pebbles of red ochre dating back 10,000 years).

In the Neolithic, many dolmens, dating from 4,000 years ago, were erected all around the cave (Bidot (classified), Cap-del-Pouech and Seignas (classified)). Pottery was found at the entrance of the cave.