A son of Cicero's intimate friend C. Avianius Flaccus, sharing his father's praenomen Gaius; an intimate of Cicero whom he held uniquely dear. In 46 BC he was in Sicily, and Cicero commends him and his brother Marcus to A. Allienus, proconsul (Fam. 13.79). Distinct from his father (person:c-avianius-flaccus); the shared praenomen makes the two hard to disentangle.