monastic reformer who was abbess of the important Jansenist centre of Port-Royal de Paris. She was one of six sisters of the prominent Jansenist theologian Antoine Arnauld (the Great Arnauld).

Jacqueline Arnauld entered religious life as a child of 9, becoming abbess of the ancient Cistercian house of Port-Royal des Champs (near Versailles) when she was not yet 12. She had become a nun only by the decision of her parents and had had no vocation for a monastic life, but in 1608 she was converted by a visiting Capuchin friar's sermon. She then undertook to reform her monastery. After an arduous struggle, even against her own family, she succeeded, and Port-Royal became a house of deep spirituality. Mère Angélique was later engaged in the reform of several other convents, especially Maubuisson. From 1618 to 1622 she was under the guidance of St. Francis of Sales. It was she who, in 1625–26, transferred the community of Port-Royal des Champs to Paris. In 1635 she came under the influence of the abbot of Saint-Cyran, one of the founders of Jansenism, a Roman Catholic movement that propounded heretical doctrines on the nature of free will and predestination. The period of persecution of Jansenists in France (1661–69) was in its early stages when, from her deathbed, Mère Angélique wrote to the Queen Mother protesting the constraint that had been inflicted on the Port-Royal community.