Felix II was a Roman archdeacon who served as an antipope beginning in 355. He was installed by Emperor Constantius II following the banishment of Pope Liberius, who had refused to condemn Saint Athanasius. After the Roman people successfully petitioned for the return of Liberius, Felix was forced to retire to Porto. He eventually died in Ceri on November 22, 365. Historical confusion regarding his identity with a different Roman martyr led to his inclusion in lists of popes and affected the numbering of later figures with the same name.