A Doctor of the Church is a title given by the Catholic Church to saints recognized for their outstanding contributions to theology or doctrine through their research, study, or writing. This title is conferred on individuals whose works have greatly benefitted the Church and are considered to be both orthodox and universally applicable to all Christians.

The term “Doctor” comes from the Latin word docere, meaning “to teach.” Doctors of the Church are seen as teachers whose writings and theological insights have helped to define and clarify important points of Christian doctrine, faith, and practice. Their teachings are held to be consistent with the faith and are recommended as models for others to follow.

The title Doctor of the Church has its roots in the early centuries of Christianity, but it was not formalized until much later. Traditionally, the “Four Great Doctors of the Western Church” were the earliest saints to be regarded with this distinction:

• Saint Ambrose (340–397)
• Saint Augustine (354–430)
• Saint Jerome (347–420)
• Pope Gregory I (Gregory the Great) (540–604)

In the Eastern Church, the equivalent title was given to three saints, known as the Three Holy Hierarchs:

• Saint Basil the Great (c. 329–379)
• Saint Gregory of Nazianzus (c. 329–390)
• Saint John Chrysostom (c. 347–407)

Although the title “Doctor of the Church” was only formally introduced by the Western Church in the Middle Ages, many early Christian thinkers were informally recognized for their contributions long before this.

To be recognized as a Doctor of the Church, three criteria must be met:

• Orthodoxy of Doctrine: The saint’s teachings must align with the essential beliefs of the Catholic Church and must not contradict established doctrine.
• Eminent Learning: The saint must have made significant contributions to Christian theology, showing exceptional wisdom and knowledge of the faith.
• Sanctity: The saint must be recognized for a life of exceptional holiness.

The title is conferred posthumously by the Pope or an Ecumenical Council, and it is often a rare honor. As of 2024, the Catholic Church recognizes 37 Doctors of the Church.

In addition to the original Great Doctors, other saints have been designated as Doctors over the centuries. Here are a few notable examples:

• Saint Thomas Aquinas (1225–1274): Known for his work in systematic theology and philosophy, particularly his Summa Theologica, Aquinas is one of the most influential theologians in the Catholic tradition.
• Saint Teresa of Ávila (1515–1582): A Spanish Carmelite mystic and reformer, Teresa was the first woman to be named a Doctor of the Church, recognized for her writings on prayer and the spiritual life.
• Saint John of the Cross (1542–1591): A Spanish mystic, reformer, and poet, John is famous for his works on the contemplative life, particularly The Dark Night of the Soul.
• Saint Catherine of Siena (1347–1380): One of the first two women to be declared a Doctor of the Church, she is known for her theological writings and her influence on the papacy during the Western Schism.
• Saint Therese of Lisieux (1873–1897): Also known as “The Little Flower,” she was named a Doctor of the Church in 1997 for her “Little Way” of spiritual childhood, teaching profound trust in God.

For centuries, all Doctors of the Church were male, but in the 20th century, women began to be recognized for their contributions. There are currently four women who hold the title:

• Saint Teresa of Ávila (1970)
• Saint Catherine of Siena (1970)
• Saint Thérèse of Lisieux (1997)
• Saint Hildegard of Bingen (2012): A 12th-century Benedictine abbess, mystic, composer, and theologian known for her extensive writings on theology, medicine, and music.

The Doctors of the Church come from various periods of Christian history, each contributing uniquely to the development of Catholic theology:

• Systematic Theology: Doctors like Thomas Aquinas and Albertus Magnus laid the foundations for systematic theology, integrating faith with reason and developing key doctrines on the nature of God, the sacraments, and the nature of the Church.
• Mysticism: Saints like Teresa of Ávila, John of the Cross, and Hildegard of Bingen enriched Christian spirituality through their writings on mysticism and the experience of God.
• Scripture and Exegesis: Early Doctors like Jerome and Augustine made critical contributions to biblical studies, with Jerome famously translating the Bible into Latin (the Vulgate).
• Church-State Relations: Ambrose and Gregory the Great are known for shaping the relationship between the Church and secular rulers, especially in terms of Church authority and the moral duties of kings and emperors.

The title Doctor of the Church continues to hold great significance. It recognizes the universal relevance of the saint's teachings, their profound intellectual and spiritual legacy, and their exemplary model of holiness. The works of the Doctors are often used in theological education, and their writings remain influential in shaping the Church’s understanding of doctrine, spirituality, and ethics.

The Catholic Church honors these figures annually in the liturgical calendar, with special Masses dedicated to them, and their writings are encouraged for study by clergy, theologians, and the faithful.

• Saint Athanasius of Alexandria (296–373)
• Saint Gregory of Nazianzus (329–390)
• Saint John Chrysostom (347–407)
• Saint Augustine of Hippo (354–430)
• Saint Leo the Great (400–461)
• Saint Anselm of Canterbury (1033–1109)
• Saint Thomas Aquinas (1225–1274)
• Saint Bonaventure (1221–1274)
• Saint Alphonsus Liguori (1696–1787)
• Saint Teresa of Ávila (1515–1582)
• Saint Therese of Lisieux (1873–1897)

The Doctors of the Church, through their writings and example, have been instrumental in shaping the theological and spiritual direction of Christianity across centuries.