John IV
John IV may refer to:
- Patriarch John IV of Alexandria, Patriarch between 569 and 579
- John IV of Armenia, Catholicos of Armenia between 833 and 855
- John IV of Constantinople, Patriarch from 582
- Pope John IV, Pope from 640
- Pope John IV of Alexandria, Coptic Pope from 777 to 799
- John IV
- John IV of Naples, Duke from 997 to after 1002
- John IV of Gaeta
- John IV of Ohrid, Archbishop of Ohrid in 1139/43–1157/64
- John IV, Count of Soissons
- John IV Laskaris, Emperor of Nicaea from 1259 to 1261
- John IV, Duke of Brittany, Count of Montfort, 7th Earl of Richmond
- John IV, Lord of Arkel
- John IV, Count of Sponheim-Starkenburg
- John IV, Duke of Saxe-Lauenburg
- John IV, Duke of Mecklenburg
- John IV, Count of Katzenelnbogen
- John IV, Count of Armagnac, Count of Armagnac, Fézensac, and Rodez
- John IV, Duke of Brabant
- John IV of Trebizond, Emperor of Trebizond
- John IV, Count of Nassau-Siegen, Count of Nassau, Vianden and Diez
- John IV, Marquess of Montferrat
- Jan IV of Oświęcim, Duke of Gliwice
- John IV, Duke of Bavaria
- John IV, Landgrave of Leuchtenberg
- John IV, Duke of Krnov, Duke of Wodzisław Śląski
- John IV of Chalon-Arlay, prince of Orange
- Ivan IV the Terrible, Czar of Russia
- John IV, Count of Nassau-Idstein
- John IV of Portugal, known as John II, Duke of Braganza, before 1640
- Yohannes IV of Ethiopia
- Jean, Count of Paris, Orléanist pretender to the French throne as Jean IV