Who was proconsul of Achaia when the Jews of Corinth brought Paul before the judgment seat?

Answer: Gallio

Gallio refused to judge what he called a dispute about words, names and Jewish law, and drove them from the judgment seat.

“While Gallio was proconsul of Achaia, the Jews coordinated an attack on Paul and brought him before the judgment seat.”— Acts 18:12 (BSB)