Porphyrus of Antioch was a Patriarch of Antioch. He succeeded Flavian I in 404 and died in 412 to be replaced by Patriarch Alexander.

In the aftermath of John Chrysostom's deposal by the Synod of the Oak and a subsequent Synod in 404, John's opponents Severian, Acacius and Antiochus sought to place priests opposed to John into positions of influence. When Flavian I died shortly after the exile of John^[1] they pushed through a rapid election & consecration of Porphyrus while many residents were at the Olympic games customarily held in July or August.^[1] The populace was offended that Constantius, Flavian's adjunct and a supporter of John's, was not installed.^[1]