Montmerle Charterhouse (French: Chartreuse Notre-Dame de Montmerle du Val-Saint-Étienne, Latin: Mons Merula) is a former charterhouse, or Carthusian monastery, located in Lescheroux, in the arrondissement of Bourg-en-Bresse and the canton of Saint-Trivier-de-Courtes, in the department of Ain, France.
The first monastery established here was a Benedictine priory, founded in 1070 by Hugh d'Asnières des Bois. It was subordinate to Seillon Priory, and both were later subordinate to Joug-Dieu Abbey.
Hugh of Colemi (Hugo Coloniacum) in the Kingdom of Jerusalem granted lands to found a grange here exempt from feudal duties, in 1202.
Like Seillon, Montmerle became a Carthusian community in 1210, following a bull issued by Pope Innocent III, the 36th Carthusian foundation.
Montmerle Charterhouse was dissolved in 1792 during the French Revolution, when some of its paintings, including a number by Nicolas-Guy Brenet, were moved to the parish church of Pont-de-Vaux.
The monastery is in ruins, except for the main entrance and the mill.
Coordinates: 46°23′34″N 5°7′34″E / 46.39278°N 5.12611°E