Saint Constantine
Saint Constantine may refer to:
- Constantine I, Roman Emperor and a convert to Christianity
- Constantine of Dumnonia, King of Cornwall
- Constantine of Strathclyde, probably fictitious King of Strathclyde
- Constantine, various figures of this name
- Constantine the Jew, 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