Patriarch Sergius may refer to:
Eastern Orthodox patriarchs Sergius of Bulgaria, Patriarch of Bulgaria c. 931 – c. 940 Patriarch Sergius I of Constantinople, Patriarch 610–638 Patriarch Sergius II of Constantinople, Patriarch 1001–1019 Patriarch Sergius I of Moscow, Patriarch 1943–1944
Other patriarchs Sergius of Tella, Syriac Orthodox Patriarch of Antioch 544–546
Fictional patriarchs Patriarch Sergius XVII, a character in Xenosaga