The elder brother of Seneca the philosopher, who was tutor and for some time minister of the emperor Nero. He was “deputy”, i.e., proconsul, as in Revised Version, of Achaia, under the emperor Claudius, when Paul visited Corinth (Acts 18:12). The word used here by Luke in describing the rank of Gallio shows his accuracy. Achaia was a senatorial province under Claudius, and the governor of such a province was called a “proconsul.” He is spoken of by his contemporaries as “sweet Gallio,” and is described as a most popular and affectionate man. When the Jews brought Paul before his tribunal on the charge of persuading “men to worship God contrary to the law” (18:13), he refused to listen to them, and “drave them from the judgment seat” (18:16).
Gallio
A Roman official hears a religious complaint and declines to judge it. Acts 18 tells how the Jews bring Paul before Gallio, “the deputy of Achaia”, saying he persuades men “to worship God contrary to the law.” Before Paul can speak, Gallio decides it is “a question of words and names, and of your law” and drives them from the judgment seat. The crowd then beats Sosthenes, and “Gallio cared for none of those things.” Readers differ on whether that is wise detachment or plain indifference. Acts 18:12-17 is the whole short scene.
6 verses
Acts
And when Gallio was the deputy of Achaia, the Jews made insurrection with one accord against Paul, and brought him to the judgment seat,
Saying, This fellow persuadeth men to worship God contrary to the law.
And when Paul was now about to open his mouth, Gallio said unto the Jews, If it were a matter of wrong or wicked lewdness, O ye Jews, reason would that I should bear with you:
But if it be a question of words and names, and of your law, look ye to it; for I will be no judge of such matters.
And he drave them from the judgment seat.
Then all the Greeks took Sosthenes, the chief ruler of the synagogue, and beat him before the judgment seat. And Gallio cared for none of those things.
From Easton's Bible Dictionary
Matthew George Easton, 1897