Montaillou is a small village and commune in southern France. It is in the eastern half of the Pyrenees in the Ariège département.

• Population: 14
• Area: 8.61 km²
• Altitude: 1325 m

The town is best known for being the subject of Emmanuel Le Roy Ladurie pioneering work of microhistory Montaillou, village occitan. It analyzes the town in great detail over a thirty year period from 1294 to 1324. Then a village of some 250 people the daily routines of the people are in the records of Jacques Fournier, later Pope Benedict XII. Montaillou was one of the last bastions of the Albigensian heresy and as the local bishop Fournier launched and extensive inquisition. This involved dozens of lengthy interviews with the locals which were all faithfully recorded. When Fournier became Pope he brought he records with him and they remain to this day in the Vatican Library.

Residents of early 14th-century Montaillou

• Pierre Clergue, priest and head of the powerful Clerge family
• Bernard Clergue, brother of Pierre and the town bayle
• Raymond Clergue, younger brother of Pierre and Bernard
• Pons Clergue, the father of the Clergue brothers
• Guillaume Clergue, brother of Pons
• Raymond "Pathau" Clergue, bsatard brother of Pons
• Mengarde Clergue, the mother of the Clergue brothers
• Bérenger de Roquefort, minor noble who served as the châtelain of the town until his death in 1302
• Béatrice de Planissoles, much younger wife of Bérenger de Roquefort assumed the duties of châtelaine after his death. For a time the mistress of Pierre Clergue
• Jacques Alsen made vice-châtelaine after the death of Bérenger de Roquefort
• Raymond Roussel, the steward who took care of the estate of the châtelaine
• Guillaume Benet , head of the wealthy Benet household, first in town converted to Albigensianism
• Bernard Benet , son of Guillaume Benet, lands confiscated and forced to become a shepherd
• Raymond Belot , head of the wealthy Belot family
• Guillaume Belot, brother of Raymond
• Bernard Belot , brother of Raymond and Guillaume husband of Guillemette Benet
• Raymond Belot, sister of Raymond, Guillaume, and Bernard marries Bernard Clergue
• Alazaïs Belot, other sister who lives out of town and only visits for family occasions
• Raymonde Arsen, a servant in the Belot household
• Raymonde Testanière, a servant in the Belot household
• Guillaume Maurs , peasant stripped of his land and forced to become a shepherd, enemy of Pierre Clergue
• Arnaud Vital, the local cobbler
• Raymonde Vital, Arnaud's wife
• Raymond Maury, weaver
• Pierre Maury, son of Raymond who became a shepherd
• Jean Maury, brother of Pierre and also a shepherd but not a strong Cathar eventually married a girl in Tarragona
• Guillemette Maury, daughter of Raymond. Married to Betrand Piquier of a neighbouring village, he beat her so she fled with the aid of her brother. Later imprisoned by the inquisition.
• Prades Tavernier, originally a successful weaver from Prades d'Aillon became a Cathar parfait
• Brune Pourcel, illegitimate daughter of Prades Tavernier. A servant and later impoverished widow
• Alazaïs Rives, sister of Prades Tavernier
• Fabrice Rives, the local wine seller. Imported the wines from the towns below and sold it door to door in the village.
• Grazide Rives, daughter of Fabrice and a mistress of Pierre Clergue. She later married Pierre Lizier.
• Jean Pellissier, a shepherd
• Pierre Azéman, a staunch Catholic and relation of Bishop Jacques Fournier. After the fall of the Clergues becomes one of the towns leading figures
• Arnaud Sicre, from nearby Ax-les-Thermes , mother burned at the stake for heresy. Turned into an informer to try and win back his family property