An Augustinian priest is a member of the Order of Saint Augustine (OSA), a Catholic religious order that follows the Rule of Saint Augustine, written around 400 A.D. by Augustine of Hippo. Augustinian priests are consecrated religious who live in community, professing the evangelical counsels of chastity, poverty, and obedience, and serve God and His people in various ministries such as pastors, educators, missionaries, and spiritual directors

. The Order of Saint Augustine was officially established in 1244 when Pope Innocent IV united various hermit groups into a mendicant community. Augustinians live according to the principle of communal living inspired by the early Christian community described in the Acts of the Apostles, sharing all things in common and caring for one another according to need

. Augustinian priests take vows including chastity (celibacy), obedience to their superiors, and poverty, committing themselves to a life of service and community. They are active in pastoral care, education, mission work, and other apostolic activities while maintaining a contemplative spiritual life

. In summary, an Augustinian priest is a Catholic priest who belongs to the Order of Saint Augustine, living a communal religious life guided by the Rule of St. Augustine, dedicated to serving the Church through various ministries with a strong emphasis on community, prayer, and apostolic work.