April 15 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 15 are broadly the same, no matter which calendar is used.
Apostles Aristarchus of Apamea, Pudens, and Trophimus of the Seventy Apostles (c. 67) (see also: April 14 - Greek)
Martyrs Basilissa and Anastasia of Rome, disciples of Apostles Peter and Paul (c. 68)
Martyr Sukia (Suchias) and nineteen companions with him, including (c. 100-130):
Andrew, Anastasius, Thalaleus, Theodoretus, Ivchirion, Jordan, Quadratus, Lucian, Mimnenus, Nerangius, Polyeuctus, Jacob, Phocas, Domentianus, Victor, and Zosima (Chorimos), of Georgia, in Armenia.
Hieromartyr Theodore and martyr Pausilippus of Thrace, by the sword (c. 117-138)
Martyrs Maximus and Olympiada, in Persia (c. 249-251)
Saint Leonidas, Bishop of Athens (250)
Martyr Crescens of Myra in Lycia, by fire (3rd century) (see also: April 13 - Slavic)
Martyr Sabbas the Goth, at Buzău in Wallachia (372) (see also: April 12 - Greek and Romanian)
Saint Ephraim the Great of Atsquri (9th century) (see also: April 17)
Martyrs Maro, Eutyches and Victorinus, at Rome, under Trajan (c. 99)
Martyr Eutychius, in Ferentino in Italy.
Child-martyr Laurentinus Sossius, a boy aged five, martyred on Good Friday in Valrovina near Vicenza in Italy (485)
Saint Paternus (Paternus of Vannes, Padarn), Bishop and founder of the monastery of Llanbadarn Fawr (the great monastery of Padarn) near Aberystwyth in Wales (565) (see also: April 16)
Saint Ruadhan (Ruadan, Rodan), one of the leading disciples of St Finian of Clonard, founder and abbot of Lothra, Ireland (c. 584)
Saint Silvester, second Abbot of Moutier-Saint-Jean (Réome) near Dijon in France (c. 625)
Saint Hunna, the self-sacrificing wife of a nobleman in Alsace, now in France (679)