The title Apostolic Fathers is given to a very diverse collection of early Christian writings. These writings are traditionally regarded as having been written by authors who had been in contact with the living apostles or had been their disciples or disciples of their disciples, in other words, authors directly or indirectly associated with the apostles. The Apostolic Fathers are dated variously from the end of the first century (± 96 CE in the case of 1 Clement) to the middle of the second century (± 145 CE in the case of the Shepherd of Hernias).

This collection consists of the following texts: the letters 1 Clement (to the church in Corinth), 2 Clement (a homily or sermon in the form of a letter), the Letter of Barnabas, the letters of Ignatius (to the Philadelphians, the Magnesians, the Trallians, the Ephesians, the Romans, the Smyrnaeans and to Polycarp), the Letter of Polycarp (to the church in Philippi), the Didache (an early church order), the fragments of Papias (from his Expositions of the Words of Our Lord Jesus Christ), the Shepherd of Hernias (a visionary book on the state of church life in the church of Rome), the Martyrdom of Polycarp, the Letter of Diognetus and the fragment of Quadratus (the last two being apologies).

The interest generated by this collection of texts derived from the view that these texts represent, together with the New Testament, the oldest and most primitive stage of the history of the Christian movement, roughly representing the first 150 years of Christian history. They are therefore indispensable as sources for an understanding of the fate and history of Jesus traditions; their growth and development into Christianity as a world-wide religious movement; the earliest interpretations of the Jesus traditions, and into the historical circumstances which shaped the emerging Christian tradition. Furthermore, they represent a stage in the history of Christianity in which the Christian canon of Scripture had not yet been fixed. Some of these texts (evidenced from testimonies of the early Church Fathers) enjoyed a popularity, wide acceptance and almost canonical status in the early church even to the extent of regularly being read in the liturgy (in the case of 1 Clement). That they were important texts for the early Church may be deduced from documentary evidence: in the hand-written manuscripts of the Bible, most of them were included as appendices to codices containing the New Testament or parts thereof.