Callistus I of Constantinople | |
|---|---|
| Ecumenical Patriarch of Constantinople | |
| Church | Church of Constantinople |
| In office | June 1350 – 1353 January 1355 – August 1363 |
| Predecessor | Isidore I of Constantinople, Philotheus I of Constantinople |
| Successor | Philotheus I of Constantinople |
| Personal details | |
| Born | [?] |
| Died | August 1363 |
| Sainthood | |
| Feast day |
|
| Venerated in | Eastern Orthodox Church |
Kallistos I (Medieval Greek: Κάλλιστος; died August 1363) was the Ecumenical Patriarch of Constantinople for two periods from June 1350 to 1353 and from 1354 to 1363. Kallistos I was an Athonite monk and supporter of Gregory Palamas. He died in Constantinople in 1363.