Montréjeau (French pronunciation: [mɔ̃ʁeʒo];[3] Gascon: Montrejau) is a commune in the Haute-Garonne department in southwestern France.

Montréjeau-Gourdan-Polignan station has rail connections to Toulouse, Pau, Bayonne and Tarbes.

Montréjeau was the site of one of the French Revolution's last pitched battles between republicans and royalists.

For a brief time it flourished, even threatening the city of Toulouse.

The Directory reacted swiftly, ordering in troops which decisively defeated the rebels at Montréjeau on 1 Fructidor Year VII (18 August 1799).