Saint-Bertrand-de-Comminges Cathedral (French: Cathédrale Notre-Dame de Saint-Bertrand-de-Comminges) is a former Roman Catholic cathedral in Saint-Bertrand-de-Comminges, Haute-Garonne, southwestern France. It was the seat of the Ancient Diocese of Comminges.
Entering the nave, three distinct architectural styles can be seen at the same time:
The narthex ends in two huge pillars, each with a circumference of no less than 11.45m. Over the northern and southern walls one can see the Romanesque arches, the floor is made of marble and includes some tombs and sepulchurs. The cloister is also clearly Romanesque and offers an impressive view over the entire valley.
The Gothic part is built in the Meridional Gothic style. There is a single nave that is 55m long, 16m wide and 28m high. Over the arrow arches there are the coats of arms of the founding bishops. The stained glass windows are impressive with their intricate details, almost comparable to those of Auch.
The stalls within the choir were commissioned by Jean de Mauléon but because of the lack of documents it is impossible to name the artist that made them, although, by comparison with other stalls, these are often considered to be the work of Nicolas Bachelier, or rather, of his school which had been using artists from France, Spain and Italy. Most of the work was done in oak and walnut tree, and the choir seems to be separate from the rest of the church in that it contrasts so much with the Gothic and Romanesque parts.