The Apostolic Fathers are a small number of Early Christian authors who lived and wrote in the second half of the first century and the first half of the second century. They are acknowledged as leaders in the early church, although their writings were not included in the New Testament. They include Clement of Rome, Ignatius of Antioch, and Polycarp of Smyrna.

The label "Apostolic Fathers" has been applied to them since the seventeenth century to indicate that they were thought of as being of the generation that had personal contact with the Twelve Apostles. Thus they provide a link between the Apostles—who had personal contact with Jesus—and the later generations of Church Fathers, which includes the Christian apologists, defenders of orthodoxy, and developers of doctrine.

Famous Apostolic Fathers include St. Clement of Rome (fl. 96), St. Ignatius of Antioch, and Polycarp of Smyrna. In addition, the Didache and Shepherd of Hermas are usually placed among the writings of the Apostolic Fathers although their authors are unknown.

Ignatius of Antioch (Ancient Greek: Ἰγνάτιος, also known as Theophorus from Greek Θεοφόρος "God-bearer") (ca. 35 or 50-between 98 and 117) was among the Apostolic Fathers, was the third Bishop of Antioch, and was a student of John the Apostle. En route to his martyrdom in Rome, Ignatius wrote a series of letters which have been preserved as an example of very early Christian theology. Important topics addressed in these letters include ecclesiology, the sacraments, and the role of bishops.

Ignatius' feast day is observed on 20 December in the Eastern Orthodox Church. In the Coptic Orthodox Church of Alexandria, he is commemorated, according to its Synaxarium, on the 24th of the Coptic Month of Kiahk (which currently falls on January 2, but is equivalent to December 20 in the Gregorian Calendar due to the current 13-day Julian-Gregorian Calendar offset). His celebration is on 1 February in the General Roman Calendar of 1962. Today Western Christianity follows the Syriac churches in keeping his feast on 17 October.

Papias (Greek: Παπίας) (writing in the first third of the 2nd century) was a bishop of the early Church. Eusebius of Caesarea calls him "Bishop of Hierapolis" (modern Pamukkale, Turkey) which is 22 km from Laodicea and near Colossae (see Col. 4:13), in the Lycus river valley in Phrygia, Asia Minor, not to be confused with the Hierapolis of Syria.

His Interpretations of the Sayings of the Lord (his word for "sayings" is logia) in five books, would have been a prime early authority in the exegesis of the sayings of Jesus, some of which are recorded in the Gospel of Matthew and the Gospel of Luke, however the book has not survived and is known only through fragments quoted in later writers, with neutral approval in Irenaeus's Against Heresies and later by Eusebius in Ecclesiastical History, the earliest surviving history of the early Church.

Papias describes his way of gathering information:

Thus Papias reports he heard things that came from an unwritten, oral tradition of the Presbyters, a "sayings" or logia tradition that had been passed from Jesus to such of the apostles and disciples as he mentions in the fragmentary quote. The scholar Helmut Koester considers him the earliest surviving witness of this tradition.