| Joachim IV | |
| Patriarch Of: | Ecumenical Patriarch of Constantinople |
| Enthroned: | 1 October 1884 |
| Ended: | 14 November 1886 |
| See: | Derkes |
| Church: | Church of Constantinople |
| Predecessor: | Joachim III |
| Successor: | Dionysius V |
| Other Post: | Metropolitan of Larisa |
| Birth Name: | Nikolaos Krousouloudis |
| Birth Date: | 5 July 1837 |
| Birth Place: | Kallimasia, Chios, Ottoman Empire |
| Death Place: | Kallimasia, Chios, Ottoman Empire |
| Occupation: | Ecumenical Patriarch |
| Alma Mater: | Theological School of Chalki |
Joachim IV (Greek, Modern (1453-);: Ἰωακείμ; 5 July 1837 – 15 February 1887) was Ecumenical Patriarch of Constantinople from 1884 to 1886.