Agnes of Montepulciano, OP (28 January 1268 – 20 April 1317)[1] was a Dominican prioress in medieval Tuscany who was known as a miracle worker during her lifetime.

Agnes was born in 1268 into the noble Segni family in Gracciano, [2] a frazione of Montepulciano, then part of the Papal States.

At the age of nine, she convinced her parents to allow her to enter a Franciscan monastery of women in the city known as the "Sisters of the Sack", after the rough religious habit they wore.

[4] In 1288 Agnes, despite her youth at only 20 years of age, was noted for her devotion to the Blessed Sacrament and deep life of prayer, and was elected as the prioress of the community.

After her return, she proceeded to build a church, Santa Maria Novella in Florence, to honour the Blessed Mother, as she felt she had been commanded to do in a mystical vision several years earlier.

She also had a vision of Dominic Guzman, under the inspiration of which she led the nuns of her monastery to embrace the Rule of St. Augustine as members of the Dominican Order.

[3] By 1316, Agnes' health had declined so greatly that her doctor suggested taking the cure at the thermal springs in the neighbouring town of Chianciano Terme.

Some fifty years after her death, a Dominican friar, Raymond of Capua, who served as confessor to Catherine of Siena, wrote an account of Agnes' life.