Saint Constantine

Saint Constantine may refer to:

• Constantine I (c. 272 – 337), Roman Emperor and a convert to Christianity
• Constantine of Dumnonia (6th century), King of Cornwall
• Constantine of Strathclyde (6th century), probably fictitious King of Strathclyde
• Constantine (British saint), various figures of this name
• Constantine the Jew (fl. c.850–886), Byzantine monk
• Constantine XI, last Byzantine emperor, unofficial Catholic Saint
• St Cyril, born Constantine, Christian theologian from Thessalonica and Christian missionary among the Slavs with his brother Methodius