Gallio (Junius Annaeus Gallio) (găl´ēō), d. AD 65?, Roman proconsul in Achaea; brother of the philosopher Seneca. His name was originally Lucius Annaeus Novatus. The "Gallio Inscription," discovered at Delphi, can be dated to c.AD 51. The Acts of the Apostles relates that he refused judgment on a question of Jewish religious law when Paul was on trial before him, and later would not interfere between Sosthenes and his Greek assailants.

Gallio a person who is indifferent, from the name of a Roman proconsul of Achaia, whose refusal to take action is recorded in Acts 18:17.