The Castillonnais probably descends from the horses that inspired the Magdalenian-era paintings found, for example, at the Cave of Niaux, with Oriental and Iberian blood added later.

Like many other French breeds from the Pyrenees, the Castillonnais probably descends from the horses that inspired the Magdalenian-era paintings found, for example, at the Cave of Niaux.

[3]: 111 [4] Over time, blood from Oriental and Iberian horses was added to the breed,[3]: 111  and influenced its physical appearance and temperament.

[4][6] The breed was originally a multi-purpose horse, used for agriculture, cavalry and pulling diligences (a type of carriage).

[4] In 1996, the Castillonnais was officially recognised by the French Ministry of Agriculture,[4] due to the efforts of a small number of breed enthusiasts,[3]: 111  though by that time only 50 purebred mares remained.

[10] In November 2005, there were only around 260 existing Castillonnais, and a goal was created by the breed association to double the number of purebred mares between 2005 and 2014.

The horses are agile,[4] sure-footed on mountain paths,[11]: 55  and exhibit extended gaits, with strong engagement of the hindquarters.

[5] The Castillonnais is used mainly for pleasure riding, and it is well adapted to the mountainous terrain of the Pyrenees, which makes is useful for equestrian tourism in the area.