On Christian Doctrine is a theological text written by St. Augustine of Hippo. It consists of four books that describe how to interpret and teach the Scriptures. The first three of these books were published in 397 and the fourth added in 426. By writing this text, St. Augustine set three tasks for Christian teachers and preachers: to discover the truth in the contents of the Scriptures, to teach the truth from the Scriptures, and to defend scriptural truth when it was attacked.

Augustine, Saint，also known as Saint Augustine or Saint Austin, was an early Christian theologian and philosopher whose writings were very influential in the development of Western Christianity and Western philosophy. He was bishop of Hippo Regius (present-day Annaba, Algeria) located in the Roman province of Africa. Writing during the Patristic Era, he is viewed as one of the most important Church Fathers in the West. Among his most important works are City of God and Confessions, which continue to be read widely today.