The letters of Augustine of Hippo cover a wide range of topics: Holy Scripture, dogma and liturgy, philosophy, religious practice and everyday life. They range from full-scale theological treatises to small notes asking someone for a favour. The preserved corpus includes 308 letters, 252 written by Augustine, 49 that others sent to him and seven exchanged between third parties. 29 letters have been discovered only in the 20th century and edited in 1981 by Johannes Divjak; they are distinguished by the asterisk (*) after their number.

The preserved letters of Augustine extend over the period from his stay at Cassiciacum in 386 to his death in Hippo in 430.