Mary Ward, IBVM CJ was an English Catholic religious sister whose activities led to the founding of the Congregation of Jesus and the Institute of the Blessed Virgin Mary, better known as the Sisters of Loreto. There is now a network of around 200 Mary Ward schools worldwide. Ward was declared venerable by Pope Benedict XVI on 19 December 2009.

A religious sister in the Catholic Church is a woman who has taken public vows in a religious institute dedicated to apostolic works, as distinguished from a nun who lives a cloistered monastic life dedicated to prayer and labor, or a canoness regular, who provides a service to the world, either teaching or nursing, within the confines of the monastery. Nuns, religious sisters and canonesses all use the term "Sister" as a form of address.