April 20 - Eastern Orthodox liturgical calendar - April 22

All fixed commemorations below are observed on May 4 by Eastern Orthodox Churches on the Old Calendar.^{[note 1]}

For April 21, Orthodox Churches on the Old Calendar commemorate the Saints listed on April 8.

• Martyrs Theodore of Perge in Pamphylia, his mother Philippa, and Dioscorus, Socrates, and Dionysius (c. 138-161)^[1][2][3] (see also: April 19 - Greek)
• Martyr Alexandra the Empress, wife of Diocletian, and those with her (303):^{[1][2][4][5][note 2]} (see also: April 23)

• Martyrs Isaacius, Apollo, and Codratus, of Nicomedia.^[6][7]

• Hieromartyrs Januarius, Bishop of Benevento, and his companions (c. 305)^[1][4][8][9]

• Faustus, Proclus, and Sosius, Deacons;
• Desiderius, Reader; and
• Gantiol, Eutychius, and Acutius, laymen, at Pozzuoli.

• Saint Maximianus, Archbishop of Constantinople (434)^{[1][4][10][11]}
• Venerable Anastasius Sinaita, Abbot of the Monastery of St. Catherine at Sinai (c. 700)^{[2][4][7][12]} (see also: April 20 - Slavic)
• Martyr Karol (Charles) ^[4][13][14]

• Saint Cyprian, Bishop of Brescia (582)^{[15][note 3]}
• Saint Beuno, Abbot, of Clynnog Fawr, Wales (642)^{[1][2][15][16][note 4]}
• Saint Maelruba of Apur Crossan (Maelrubius, Maolrubha), Ireland (722)^{[1][2][15][17][note 5]}
• Saint Frodulphus (Frou), a monk at St Martin's in Autun (c. 750)^{[15][note 6]}

• Saint Theodore the Philosopher of Kamske, martyred by Mongols (1323)^[18]
• Venerable Jacob (Jakov, James), Abbot of Stromynsk Monastery, Radonezh (1392)^{[1][2][19][20][note 7]}
• Saint Alexis, Priest of, Bortsurmany, Nizhny Novgorod (1848)^[1][2][22]

• Synaxis of The Mozdok Icon of the Mother of God (Mozdokskaya) (1768)^{[2][20][25][note 10]}
• Uncovering of the relics (1999) of St. Theodore, Abbot of Sanaxar Monastery (1791)^{[1][2][22][note 11]}
• Repose of Schemamonk Nicetas of Valaam Monastery (1907)^[1]
• Repose of Elder Dometian of Tula (1908)^[1]
• Repose of Hieroschemamonk Antipas II of Valaam Monastery (1912)^[1]
• Repose of Nun Stefanida of Kosovo, Serbia.^[1]

• Martyrs Theodore of Perge in Pamphylia, his mother Philippa, and Dioscorus, Socrates, and Dionysius.
• St. Alexandra the Empress.
• Hieromartyrs Januarius, Bishop of Benevento, and his companions.
• Venerable Anastasius Sinaita, Abbot of the Monastery of St. Catherine at Sinai.
• Saint Beuno, Abbot, of Clynnog Fawr, Wales.
• New Hieromartyr Protopresbyter Basil Martysz of Teratyn.