Mont-de-Marsan (French pronunciation: [mɔ̃ də maʁsɑ̃]; Occitan: Lo Mont de Marçan[3]) is a commune and capital of the Landes department, Nouvelle-Aquitaine, southwestern France.

[4] The French Air and Space Force operates the Constantin Rozanoff Mont-de-Marsan Air Base about 2 kilometres north of the town.

Mont-de-Marsan Air Base was formerly home to France's first operational squadron of nuclear bombers, the Dassault Mirage IVA.

The city has around 9,000 sports licensees, which represents nearly 30% of its total population.

Two historic punk rock music festivals were held in Mont-de-Marsan's bullring in 1976 and 1977.