Gessius of Petra

Gessius of Petra (Greek: Γέσιος, Gesios) was an Arab physician, iatrosophist and pagan philosopher active in Alexandria in the late 5th and early 6th century.

Gessius was a native of the region of Petra. According to Damascius, who is the main source for Gessius' biography in the Suda, He may have been descended from the Gessius who was a student and correspondent of Libanius and was active in Egypt in the 4th century. He studied under Domnus, who was Jewish. Later, he is said to have lured students away from his master.

According to Zacharias Rhetor, Gessius studied philosophy under Ammonius Hermiae in Alexandria. He was also teaching medicine in Alexandria when Zacharias was living there in the 480s. Damascius says that he began his practice late, but was a famous physician during the reign of the Emperor Zeno (474–491). perhaps referring to the grant of a title by the Roman state. is the same Gessius, then he was dead by 10 May 538. In the papyrus, which was drawn up in Gaza, he is described as "of learned memory".