Family 13, also known as the Ferrar Group, is a group of Greek Gospel manuscripts, dating from the 11th to the 15th centuries, which share a distinctive pattern of variant readings. Textual critic Hermann von Soden labelled the family as Iⁱ). All are thought to derive from a lost majuscule Gospel manuscript, probably from the 7th century. The group takes its name from minuscule 13, now in Paris.

The common characteristics of Family 13 were initially identified in a group of four witnesses (minuscules 13, 69, 124, and 346); but the category has subsequently been extended, and some authorities list thirteen family members. The most obvious characteristic of the group is that these manuscripts place John 7:53-8:11 after Luke 21:38, or elsewhere in Luke's Gospel, with the text of Luke 22:43-44 placed after Matt 26:39, and the text of Matthew 16:2b–3 being absent.

Using the study of comparative writing styles (palaeography), most of the manuscripts in the family (with the exception of Minuscule 69) appear to have been written by scribes trained in Southern Italy. The group also has an affinity with Syriac manuscripts, of which a notable example is Matthew 1:16, where the Ferrar group has the same reading as Curetonian Syriac.

Textual critic Johann Jakob Wettstein observed close affinity between minuscules 13 and 69. The affinity between minuscules 124 and 13 was remarked by Treschow and its resemblance to minuscule 69 by Andreas Birch.

The first published account of Family 13 appeared in the year 1877, in a book published by T. K. Abbott on behalf of his deceased colleague (and discoverer of Family 13), William Hugh Ferrar. Before his death, Ferrar collated four minuscules (Greek handwritten cursive texts) to definitively demonstrate that they all shared a common origin. His work, A Collation of Four Important Manuscripts of the Gospels, would be the first scientific attempt to discover the lost archetype of these four minuscules.

The four minuscules Ferrar collated are:

Ferrar transcribed two of these minuscules himself, accepting a previous transcription of 69 done by another person as trustworthy and adequate. He accepted a handmade copy of 124 from the hand of Dr. Ceriani, the Conservator of the Ambrosian Library at the time. The result of his work demonstrates the members of Family 13 do indeed seem to share a common pattern of distinctive shared readings not seen in other manuscripts. In 1913, von Soden’s work on the Greek New Testament seemed to confirm the assertion this family descended from a common archetype.

In 1924 biblical scholar Burnett Hillman Streeter proposed that Family 13 should be classified as one branch of a distinct Caesarean text-type, differing in a number of common respects from the then established Byzantine, Western and Alexandrian text-types. This view is supported by some, but not all, subsequent scholars.