May 9 (Eastern Orthodox liturgics)

• Prophet Isaiah (8th century BC)^[1][2]
• Great-martyr Christopher of Lycia (c. 249–251),^[3][4] and with him:

• Martyrs Callinica (Callinike of Lycia),^[5] and Aquilina (Aquilina of Lycia)^[6] (c. 249 – 251)^[7]

• Saint Maximus III of Jerusalem, Patriarch (350)^[8] (see also: August 26)
• Saint Shio of Mgvime, monk, of Georgia (6th century)^[9][10][11]
• Monk-martyr Nicholas of Vouneni, in Thessaly (901)^[12]

• Saint Beatus, Apostle of Switzerland (2nd century)^[13]
• Martyrs Epimachus and Gordianus of Rome, in the persecution of Decius (c. 249 – 251)^[14]
• Saint John of Châlon, third Bishop of Châlon-sur-Saône in France (c. 475)^[13]
• Saint Gerontius, bishop of Cervia near Ravenna in Italy, martyr (c. 501)^[13][15]
• Saint Sanctan, Bishop of Kill-da-Les and Kill-na-Sanctan near Dublin in Ireland (6th century)^[13]
• Blessed Adalgar, third archbishop of Hamburg-Bremen (909)^[16][17]
• Saint Vincent, Abbot of St Peter de Montes in Spain, a disciple and successor of St. Gennadius of Astorga (c. 950)^[13]
• Saint Gregory, Bishop of Ostia (c. 1044)^[13]

• Saint Dmitry Donskoy, Prince of Moscow (1389)^{[18][note 2]}
• New Hieromartyr Methodius of Amaria, Crete (1793)^[21]
• Saint Joseph (Litovkin) of Optina, Hiero-schema-monk of Optina Monastery (1911)^{[22][23][note 3]}
• Venerable Elder Ieronymos of Simonopetra (1957)^{[25][note 4][note 5][note 6]} (see also: April 26 - OS)

New martyrs and confessors

• New Hieromartyr Demetrius Voskresensky, Priest (1938)^[11][30]
• New Hieromartyr Basil Kolosov, Priest (1939)^[11][30]
• New Martyrs of Slobozhanschyna (Slobodskaya Ukraine).^{[31][32][note 7]}

• Translation of the Relics of Saint Nicholas from Myra to Bari in 1087.^[11] (see also: May 20 – Greek)
• Zaraysk Icon of St. Nicholas the Wonderworker (1225)^[30]
• Translation of the relics (1775) of Child-martyr Gabriel of Slutsk (1690)^[24][30][34]

• 
  Prophet Isaiah.
• 
  Fresco of St. Christopher, (Limburg Cathedral).
• 
  St. Aquilina.
• 
  St Shio of Mgvime.
• 
  Sts. Gordianus and Epimachus (Illustration from the Nuremberg Chronicle).
• 
  Martyrdom of St. Gordianus.
• 
  St. Dmitry Donskoy.

• Complete List of Saints. Protection of the Mother of God Church (POMOG).
• May 9, OCA – The Lives of the Saints.
• May 9/22, Orthodox Calendar (PRAVOSLAVIE.RU).
• May 22 / May 9, HOLY TRINITY RUSSIAN ORTHODOX CHURCH (A parish of the Patriarchate of Moscow)
• New Martyrs and Confessors of the Soviet Yoke, Saints of the Ukrainian Orthodox Church.
• Dr. Alexander Roman. May. Calendar of Ukrainian Orthodox Saints (Ukrainian Orthodoxy – Українське Православ'я).
• May 9. Latin Saints of the Orthodox Patriarchate of Rome.
• May 9. The Roman Martyrology.

Greek Sources

• Great Synaxaristes: (in Greek) 9 ΜΑΪΟΥ. ΜΕΓΑΣ ΣΥΝΑΞΑΡΙΣΤΗΣ.
• (in Greek) Συναξαριστής. 9 Μαΐου. ECCLESIA.GR. (H ΕΚΚΛΗΣΙΑ ΤΗΣ ΕΛΛΑΔΟΣ).

Russian Sources

• (in Russian) 22 мая (9 мая). Православная Энциклопедия под редакцией Патриарха Московского и всея Руси Кирилла (электронная версия). (Orthodox Encyclopedia – Pravenc.ru).
• (in Russian) 9 мая (ст.ст.) 22 мая 2013 (нов. ст.). Русская Православная Церковь Отдел внешних церковных связей. (DECR).