Anastasius I of Thessaloniki

Holy Hierarch Anastasius I of Thessaloniki was archbishop of Thessalonica in the first half of the fifth century. The Church commemorates him on 16 July.

He succeeded Rufus on the throne, probably in the year 434. In 435 Pope Sixtus III wrote to Bishop Perigenes of Corinth, reminding him that he must submit to the bishop of Thessalonica and papal vicar Anastasius, the successor of Rufus. In the same year the pope sent a second letter, addressed to the synod that was to meet at Thessalonica, confirming the rights that Anastasius's predecessors had enjoyed as papal vicars. A few years later, in 446, Pope Leo I sent him a letter concerning his dispute with Metropolitan Atticus of Epirus and confirmed his rights again.

For reasons unknown, Anastasius could not take part personally in the Fourth Ecumenical Council at Chalcedon in 451. At the first session, on 8 October 451, he was represented by Bishop Quintillus of Heraclea. At the third session, on 13 October, the name of the bishop of Thessalonica was already Euxitheus (or Eudoxius), represented by the presbyter Andrew.