April 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 April 18 are broadly the same, no matter which calendar is used.
Martyrs Victor, Zoticus, Zeno, Acindynus, and Severian, of Nicomedia (c. 303) (see also: April 20 - Greek)
Martyr Sabbas the Goth (Sabbas Stratelates), at Buzau in Wallachia (372) (see also: April 12 and April 15)
Saint Acacius II, Bishop of Melitene (445) (see also: April 17)
Saint Cosmas, Bishop of Chalcedon, and his fellow-ascetic St. Auxentius (815-820)
Venerable John the Righteous (John the Hesychast), disciple of St. Gregory of Decapolis (c. 820-850)
Venerable Naucratius, Abbot of the Studion (848)
Venerable Athanasia the Wonderworker, Abbess, of Aegina (850) (see also: April 12 - Slavic)
Venerable Matthew (Matthias), acquaintance of St. Athanasia the Wonderworker (c. 850)
Venerable Euthymius the Wonderworker.
Saint Eleutherius, Bishop of Illyria, his mother Anthia, and eleven others, martyred in Illyria under Hadrian (c. 117-138) (see also: December 15 - East)
Martyr Corebus, a prefect of Messina in Sicily, converted to Christ by St Eleutherius and martyred under the Emperor Hadrian (c. 117-138)
Martyr Calocerus, an officer of the Emperor Hadrian martyred in Brescia in Italy (c. 117-138)
Saint Apollonius the Apologist, a Roman senator, denounced as a Christian by one of his own slaves and condemned to be beheaded (c. 190)
Saints Bitheus and Genocus, two monks from Britain who accompanied St Finian of Clonard to Ireland (6th century)
Saint Laserian (Molaisse), founder of the monastery and bishopric of Leighlin in Ireland (639)
Saint Deicola (Dicul), born in Ireland, he preached Christ in England in Norfolk and in Sussex (late 7th century)
Saint Agia (Aia, Aya, Austregildis, Aye), wife of St Hidulf of Hainault in Belgium, monastic at the convent of Mons (c. 714)