January 18 in Eastern Orthodox liturgical calendars is a feast day and a day of commemoration of saints and martyrs. Although some Orthodox churches use the Revised Julian Calendar and others use the traditional Julian calendar, the fixed commemorations for their respective January 18 are broadly the same, no matter which calendar is used.
Martyr Theodula and her companions Helladius, Theodoulos, Boethius, Evagrius, and Macarius, of Anazarbus, Cilicia (c. 304)
Saint Athanasius the Great, Patriarch of Alexandria (373)
Venerable Marcian, Monk of Cyrrhus, Syria (c. 388)
Venerable Silvanus (Sylvanus) the Ascetic of Gaza, Palestine (before 414)
Saint Cyril, Patriarch of Alexandria (444)
Venerable Ephraim (Ephraimios), Bishop of Mylasa, Caria, Asia Minor (5th century)
Virgin Martyr Prisca, venerated from ancient times in Rome, where a church is dedicated to her on the Aventine (1st or 3rd century)
Martyrs Archelais, Thecla and Susanna, three holy virgins, at Salerno (293) (see also: June 6)
Saint Volusianus of Tours, a married senator who was chosen Bishop of Tours in France and shortly after driven out by Arian Visigoths (496)
Saint Liberata of Como, a holy virgin in Como in Italy where with her sister Saint Faustina she founded the convent of Santa Margarita (580)
Saint Leobardus the Recluse of Marmoutier, Gaul (593)
Saint Ninnidh of Inishmacsaint (Inismacsaint), Ireland (6th century) (see also: January 17)
Saint Deicolus, one of the twelve disciples to accompany St. Columbanus in his missionary enterprise (625)
Saint Ulfrid (Wolfred, Wulfrid, Wilfrid), missionary in Germany and Sweden, martyred for destroying an image of Thor (1028)
Venerable Ephraim the Lesser (the Philosopher) of Georgia (1101)
Venerable Cyril, Abbot of Kiev (1146)
Saint Joachim I, Patriarch of Tarnovo (Turnovo, Trnovo) and Bulgaria (1248)