Ambrose of Alexandria (died about 250 AD) was a friend of Origen.

Attracted by Origen's fame as a teacher, he visited his school about 212, and was converted by Origen from the Valentinian heresy to the orthodox faith (Eusebius, Church History, VI. xviii. 1).

He was a sufferer during the persecution under Maximinus Thrax in 235 (Eusebius, Church History, VI. xxviii.), and is last mentioned in Origen's Contra Celsum, which the latter wrote at the solicitation of Ambrose.

He was wealthy and provided his teacher with books for his studies and secretaries to lighten the labor of composition (Eusbius, Church History, VI. xxiii. 1-2; Jerome, De vir. ill., lvi.).

Origen often speaks of him in terms of affection as a man of education and literary and scholarly tastes. All of his works written after 218 are dedicated to Ambrose.