Gregory IV can refer to:
Pope Gregory IV (827–844) Gregory IV of Naples (898–915) Gregory IV the Young (1173-1193) Patriarch Gregory IV of Alexandria (1398–1412) Patriarch Gregory IV of Constantinople (1623) Gregory IV of Athens (died 1828), Albanian scholar and cleric; Metropolitan of Athens 1827–1828 Gregory IV of Antioch (1859–1928), Greek Orthodox Patriarch of Antioch 1906–1928