Gnaeus Gellius (fl. 2nd half of 2nd century BC) was a Roman historian. Very little is known about his life and work, which has only survived in scattered fragments. He continued the historical tradition set by Fabius Pictor of writing a year-by-year history of Rome from mythological times to his day. However, with about a hundred books, Gellius' Annales were massively more developed than the other Roman annalists, and was only surpassed by Livy's gigantic History of Rome.