Mary Jane Guillén was an Augustinian Sister noted for her gifts of ecstatic prayer, prophecy and understanding of the Sacred Scriptures.

Mary Jane Guillén (1575-1607) was born December 25, 1575 in Orihuela, Alicante, Spain. Her parents raised her in an exemplary manner.

While still young, she promised that she would always remain a virgin. She rejected several marriage proposals. When she entered the Augustinian monastery of Saint Sebastian in 1597, Mary Jane was already considered to be a holy woman by those who knew her.

At the young age of 26, Mary Jane was elected Director of Novices. She carried out this office so well that not only the Novices, but the Professed Sisters as well, would listen to her teaching.

She was a model Sister, totally absorbed in God, virtuous and on fire with love for others. She was especially devoted to the Holy Trinity, the child Jesus, the Eucharist, the Passion of Christ, the Blessed Mother, Saint John the Evangelist, Saint Augustine and Saint Nicholas of Tolentine.

She experienced the prayer of ecstasy and many visions. She was given the gifts of prophecy and tears, and had a remarkable understanding of the Word of God in the Bible. All these gifts did not make her proud. She remained humble and modest and continually practiced prayer and works of penance.

Mary Jane died a holy death June 2, 1607.

Because of the many graces obtained through her intercession, the Bishop of Orihuela began her process of beatification and canonization in 1615. In 1619, the process was sent to Rome. However, the person carrying the documents relating to Mary Jane's process died. All the records were lost at that time and did not reappear until 1886. Finally, in 1896 her cause was formally introduced in Rome. The validity of her cause was approved in 1929. A decree recognizing her virtuous life was published in 1970. Josef Sciberras, O.S.A., the Augustinian Postulator of Causes, now oversees the progress of Mary Jane's cause.