Gratian can refer to:
- Felinus and Gratian (d. 250 AD), Christian martyrs and saints
- Gratianus Funarius, Roman soldier, father of emperors Valentinian I and Valens
- Gratian, Roman emperor from 367 to 383
- Gratian, a 5th-century Romano-British usurper and emperor
- Pope Gregory VI (died 1047), whose name was John Gratian before he assumed the papacy
- the author of the 12th-century Decretum Gratiani
- Gratian of Tours (Gatian), bishop of Tours