- Source: Ioannes IV
- Ioannes IV Laskaris
- Anna dari Hohenstaufen
- Andronikos IV Palaiologos
- Laskaris
- Ioannes Pitzigaudes
- Orhan
- Theodoros II Laskaris
- Mikhaēl IV Paphlagōn
- Ioannes VIII Palaiologos
- Daftar kaisar Romawi Timur
- Ioannes IV
- Pope John IV
- John IV of Trebizond
- Ioannes (given name)
- John IV
- Ivan the Terrible
- John IV Laskaris
- Patrologia Latina
- John IV of Constantinople
- Juan Diego
Ioannes IV (Ancient Greek: Ἰωάννης Δ΄, Iōannēs D΄) may refer to:
Patriarch John IV of Constantinople (died in 595)
John IV, Archbishop of Ohrid (c. 1088 – 1163/64)
John IV Laskaris (1250–c. 1305)
John IV Megas Komnenos (c. 1403–1459), emperor of Trebizond
See also
John IV (disambiguation)