Alet Cathedral (Cathédrale Notre-Dame d'Alet) was a Roman Catholic church located in the town of Alet-les-Bains in Languedoc, France. The cathedral is in the Gothic architectural tradition.

The Diocese of Alet was one of several bishoprics created in 1317 in the wake of the suppression of the Cathars. In Alet the bishops were also the abbots of the already existing monastery there and the cathedral of Our Lady (Notre-Dame) was built next to the abbey.

In 1577 it was largely destroyed by the Huguenots during the Wars of Religion and was not subsequently rebuilt. The immense Gothic quire was demolished by order of the last bishop, Charles de la Cropte de Chancerac in 1776. The diocese of Alet was not restored after the French Revolution and by the Concordat of 1801 its parishes were added to the Diocese of Carcassonne.

The cathedral's stone ruins, which were listed as a monument historique in 1862, remain a spectacular sight.

As the main cathedral was for so long in ruins, part of the monastic buildings were used as an emergency substitute. These premises were known as St. Benedict's Cathedral (Cathédrale Saint-Benoît d'Alet).

• "Église d'Alet" in Claude Devic, Joseph Vaissète, Ernest Roschach, Histoire générale de Languedoc, Édouard Privat libraire-éditeur, Toulouse, 1872, tome 4, pp. 422–424 (lire en ligne) [archive]
• Gratien Leblanc, "L'ancienne cathédrale d'Alet", pp. 254–290, in Congrès archéologique de France. 131e session. Pays de l'Aude. 1973, Société Française d'Archéologie, Paris
• Gratien Leblanc, "Vestiges conservés de l'ancienne abbaye d'Alet", pp. 291–303, in Congrès archéologique de France. 131e session. Pays de l'Aude. 1973, Société Française d'Archéologie, Paris
• Jean Nougaret, "Sainte-Marie d'Alet", pp. 155–180, in Languedoc roman, Éditions Zodiaque, Collection La nuit des temps, no. 43, Saint-Léger-Vauban, Abbaye Sainte-Marie de La Pierre-qui-Vire, 1975, 419 p.
• Jean-Marie Pérouse de Montclos (dir.), Le guide du patrimoine. Languedoc-Roussillon, Hachette, 1996, 606 p., (ISBN 9782012423336), pp. 125–128.

• Languedoc Info: Alet Cathedral
• (in French) Culture.gouv.fr: Cathedrals of Languedoc-Roussillon
• Pictures of the cathedral