Faustus Cornelius Sulla Felix (22–62) was one of the lesser known figures of the Julio-Claudian dynasty of ancient Rome.
Felix was the son of Domitia Lepida the Younger and the suffect consul of 31, Faustus Cornelius Sulla Lucullus, a descendant of the Roman Dictator Lucius Cornelius Sulla. His maternal grandparents were Antonia Major and Lucius Domitius Ahenobarbus (consul 16 BC). His maternal grandmother Antonia Major was a niece of the Roman emperor Augustus and his mother, Domitia Lepida, was a great-niece of Augustus, being a granddaughter of Augustus’ sister Octavia the Younger and Roman Triumvir Mark Antony. Felix was a maternal younger half-brother of the Roman empress Valeria Messalina.
In 47 the Roman emperor Claudius, which was his mother’s cousin arranged for Felix to marry his daughter, Claudia Antonia. Antonia bore Felix a son, who was reportedly frail and died before his second birthday. The boy’s first birthday was celebrated privately. Felix's attachment to the imperial ruling family brought him an early consulship in 52.
In 56, two years after the accession of Roman emperor Nero, the imperial freedman Pallas and the Praetorian prefect Sextus Afranius Burrus were accused of conspiring to have Felix declared emperor. The conspirators were put on trial, but Felix does not appear to have been implicated. Nero however, began to watch his brother-in-law closely, afraid of his connection to the imperial family.
In 58 another imperial freedman falsely accused Felix of plotting to attack Nero, possibly at the latter's instigation. Nero treated Felix as proven guilty, had him exiled in 59 and confined to Massilia (modern Marseille, France). Finally in 62, the palace guardsman Tigellinus sent assassins to murder Felix. He was murdered at dinner; five days after Tigellinus gave his orders. Felix’s head was transported to the palace. At times, Nero would tease his head, due to his baldness and greyness to his hair. The Historian Tacitus described Felix’s character as "timid and despicable" and also stated that Felix was incapable to attempt to plot against Nero.