Saint Cyril (Latin: Cyrillus) may refer to:

• Cyril of Jerusalem (c. 313–386), Christian theologian
• Cyril of Alexandria (c. 376–444), Patriarch of Alexandria
• Saint Cyril the Philosopher (826–869), Christian theologian and missionary, credited with devising the Glagolitic alphabet
• Pope Cyril II of Alexandria (1078–1092), Patriarch of Alexandria
• Kirill of Turov (1130–1182), Christian theologian and bishop
• Pope Cyril V of Alexandria (1874–1927), Patriarch of Alexandria
• Pope Cyril VI of Alexandria (1902–1971), Patriarch of Alexandria

• Cyril (disambiguation)
• Saints Cyril and Methodius (disambiguation)
• St. Cyril's Monastery (disambiguation)