Albert Barnes on Acts 18:24

And a certain Jew named Apollos. Apollos afterwards became a distinguished and successful preacher of the gospel, 1Cor 1:12; 1Cor 3:5,6, 4:6, Tit 3:13. Nothing more is known of him than is stated in these passages.

Born at Alexandria. Alexandria was a celebrated city in Egypt, founded by Alexander the Great. There were large numbers of Jews resident there. Acts 6:9.

An eloquent man. Alexandria was famous for its schools; and it is probable that Apollos, in addition to his natural endowments, had enjoyed the benefit of these schools.

Mighty in the Scriptures. Well instructed, or able in the Old Testament. The foundation was thus laid for future usefulness in the Christian church. Lk 24:19.

(f) "named Apollos" 1Cor 1:12, 3:5,6, Tit 3:13