Marcus Aurelius Claudius Quintillus (d. 270) was brother of the Roman Emperor Claudius II, and the Emperor himself in 270.

Historia Augusta reports him becoming Emperor in a coup d'état. Eutropius reports Quintillus to have been elected by soldiers of the Roman army immediately following the death of his brother. The choice was reportedly approved by the Roman Senate. Joannes Zonaras however reports him elected by the Senate itself.

Records however agree that the legions which had followed Claudius to campaigning by the Danube were either unaware or disapproving of Quintillus' elevation. They instead elevated their current leader Aurelian to the rank of Augustus. Historia Augusta reports Aurelian to have been chosen by Claudius himself as a successor. Apparently a deathbed decision.

Reign of Quintillus

The few records of Quintillus' reign are contradictory. They disagree on the length of his reign, variously reported to have lasted as few as 17 days and as many as 177 days (about six months). Records also disagree on the cause of his death. Historia Augusta reports him murdered by his own soldiers in reaction to his strict military discipline. Jerome reports him killed, persumably in conflict with Aurelian. John of Antioch and Joannes Zonaras reported Quintillus to have commited suicide by opening his veins and bleeding himself to death. John reports the suicide to have been assisted by a physician. Claudius Salmasius pointed that Dexippus recorded the death without stating causes. All records however agree in placing the death at Aquileia.

Quintillus was reportedly survived by his two sons.

Historia Augusta reports Claudius and Quintillus having another brother named Crispus and through him a niece. Said niece Claudia reportedly married Eutropius and was mother to Constantius Chlorus. Historians however suspect this account to be a genealogical fabrication by Constantine the Great.

Surviving Roman records considered Quintillus a moderate and capable Emperor. He was seen as a champion of the Senate and thus compared to previous Emperors Servius Sulpicius Galba and Publius Helvius Pertinax. All three were highly regarded by Senatorial sources despite their failure to survive a full year of reign.