The City of God is a book of Christian philosophy written in Latin by Augustine of Hippo in the early 5th century AD. It is one of Augustine's major works, standing alongside The Confessions, The Enchiridion, On Christian Doctrine, and On the Trinity. Augustine is considered the most influential Father of the Church in Western Christianity, and The City of God profoundly shaped Western civilization.

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.