Joannicius, also Ioannikios (), Joanikije (), Ioannikiy (), Anikey (), Anikiy (), Ioannykiy (), Onykiy (), may refer to:
Joannicius the Great, 8th-century Byzantine Christian saint Joannicius of Ochrid, Archbishop of Ohrid (13th century) Joannicius of Devič, died 1430 Patriarch Joannicius I of Constantinople, reigned 1524–1525 Patriarch Joannicius II of Constantinople, reigned four times in 1646–1656 Patriarch Joannicius III of Constantinople, reigned 1761–1763; Patriarch of the Serbs 1739–1746 Patriarch Joannicius of Alexandria, Greek Patriarch of Alexandria 1645–1657 Joannicius, Metropolitan of Moscow, reigned 1882–1891
See also Joanikije, a given name