The Church of Saint Porphyrius is a Greek Orthodox church in Gaza City, State of Palestine. It belongs to the Greek Orthodox Patriarchate of Jerusalem and is the oldest active church in the city. Located in the Zaytun Quarter of the Old City of Gaza, it is named after the 5th-century bishop of Gaza, Saint Porphyrius, whose tomb is situated in the northeastern corner of the church.

Porphyrius was bishop of Gaza from 395 to 420, known, from the account in his Life, for Christianizing the recalcitrant pagan city of Gaza, and demolishing its temples.