Joannicius I of Constantinople (Greek: Ἰωαννίκιος; died c. 1526) was Ecumenical Patriarch of Constantinople briefly in 1524–1525.
Patriarch Jeremias I of Constantinople, shortly after his election, travelled to Cyprus, Egypt, Sinai and Palestine.
While he stayed in Jerusalem, the clergy and the notables of Constantinople, annoyed by his long absence,[2] deposed him on April or May 1524, and elected in his place the Metropolitan of Sozopolis in Thrace, Patriarch Joannicius I. Jeremias I reacted and together with the Patriarchs of Alexandria and Antioch, whom he called to Jerusalem, he excommunicated Joannicius I.
[2] Even if the majority of the Holy Synod sided with Joannicius I, the Sultan Suleiman the Magnificent ordered Jeremias I to be re-installed on the throne, which took place in Constantinople on 24 September 1525.
Joannicius I returned to Thrace, where he died in the monastery of Saint John the Baptist[3] near Sozopolis circa 1526.