The Landais is a critically-endangered French breed of small horse or pony. It originated in the marshy plains and woodlands of the département of the Landes, in the Nouvelle-Aquitaine region of south-western France, but is more often reared in the département of Pyrénées-Atlantiques, particularly in the arrondissement of Pau. Due to influences from Arab and Welsh blood, it shows more similarity to Oriental horses than to other Celtic breeds.^[3]: 482 It is used for riding and driving, and is a good trotter.

Traditionally, two distinct types of pony or small horse lived in a feral or semi-feral state in the Landes de Gascogne region of south-western France: the Lédon or Poney des Pins in the sandy coastal areas of the Gironde and the Haute-Lande [fr]; and the Barthais in the Barthes de l'Adour [fr], the marshy meadowlands of the valley of the Adour river.^[4][5]

The plantation of the Landes forest and associated swamp drainage operations in the nineteenth century reduced the natural range of these horses. In 1913 the two populations totalled some 2000.^{[4][6]: 186} The advent of motorised transport led to a decline in the number of animals, both because their usefulness was reduced and because some were the cause of road accidents; during the Second World War, some fell victim to land-mines laid by German forces to prevent coastal landings. After the War, no more than 150 head remained.^[4] The Poney des Pins became extinct in about 1950.^[4][5]

Recovery of the breed – which now consisted only of the Barthais type – began in 1967,^[4] and a stud-book for the Landais was established in that year.^[7] To reduce the effects of inbreeding, some use was made of stallions of Arab and Welsh (Section B) types.^{[4]: 149 [8]}

In 2007 the Landais was listed by the FAO as "critically endangered";^[1]: 44 in 2014 the total number reported for the breed was 159.^[7] Annual births are low: between 2006 and 2013 the number ranged from 36 to 66.^[5]

A genetic study of French horse breeds in 2008 suggested that, to maximise genetic diversity among the French horse population, conservation priority be given to the Landais and four other breeds.^[9]: 5

Some Landais ponies live in a semi-feral state with other livestock and wildlife on the banks of the Adour and Luy rivers in the area of Dax in the Landes,^[4] but the largest number is found in the arrondissement of Pau, in the département of Pyrénées-Atlantiques.Others are reared elsewhere in Nouvelle-Aquitaine, and in the Auvergne-Rhône-Alpes, Centre-Val de Loire, Occitanie and Pays de la Loire regions.^[5]

The Landais shows more similarity to Oriental horses than to Celtic breeds.^[3]: 482 Arab influence can be seen in the head, while the small upright ears are from the Welsh heritage.^[6]: 186 The legs are fine, the shoulders sloped, and the rump sloping and single. The mane is full, as is the tail, which is carried high.^{[2][6]: 186} The colours are bay, black, chestnut, liver chestnut, and seal brown;^{[2]: 8 [5]} White markings to the face and legs are permitted.^[2]: 8

The Landais is used as a riding horse – often by children – for hacking out and trekking, and in competition sports such as jumping, eventing and dressage.^[5] It is an excellent trotter, and is used in trotting races and in competitive driving; a Landais named Jongleur holds the trotting record for the 100-kilometre (62-mile) run between Paris and Chartres.^[5]

The Landais was among the breeds used in the creation of the Poney Français de Selle or French Riding Pony.^[6]: 186