 Marguerite was born into the locally powerful family of the seigneurs of Oingt in Beaujolais, who became extinct in 1382 for want of male heirs.She joined the Carthusian Order as a nun, and in 1288 became the fourth prioress of Poletains Charterhouse, near Mionnay in the Dombes, founded in 1238 by Marguerite de Bâgé for nuns who wished to live according to the custom of the Carthusians as far as was then thought possible for women.Marguerite d'Oingt was also a well-known mystic of her day, contemporary with Philippe le Bel and Pope Clement V.

Along with Marie de France, Marguerite is one of the first women writers in France of whom any record survives.