Quintus Marcius Dioga was a Roman eques who flourished during the reign of the emperor Septimius Severus and his sons. He was appointed to a series of imperial offices, including praefectus annonae, (overseer of the grain supply for Rome), and praefectus vigilum (commander of the night watch of Rome). Based on an inscription found in Lepcis Magna to Divus Pius Severus Augustus, led to believe Dioga was a native of that African city and "Septimius Severus was responsible for making the fortune of his compatriot, as he had for many others."