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