SOSTHENES (sŏs'thĕ-nēz, Gr. Sōsthenēs). The apparent successor of Crispus, the ruler of the synagogue at Corinth. During Paul’s first visit in that city, Sosthenes was beaten by the crowd in the presence of Gallio, the Roman proconsul of Achaia (Acts.18.17). No reason is given for this action, but it is likely that they took “advantage of the snub that the proconsul had administered to the leaders of the Jewish community” to vent their anti-Semitic sentiment (F. F. Bruce, The Book of Acts, 1956, p. 375). It is quite possible that he subsequently became a Christian, for a Sosthenes joins Paul in the salutation of 1Cor.1.1. If this is not the Sosthenes of Acts.18.1-Acts.18.28, he is otherwise unknown in the NT.

SOSTHENES sŏs’ thĭ nez (Σωσθένης, G5398). 1. Ruler of the synagogue at Corinth during Paul’s first visit there (Acts 18:17). Successor to Crispus who had become a Christian, Sosthenes was seized and beaten by the crowd before the tribunal after Gallio, proconsul of Achaia, had dismissed a Jewish prosecution of Paul (18:17). He was the victim either of an anti-Sem. demonstration by Greeks (KJV) or Jewish spite against an unsuccessful spokesman.

2. Co-sender of 1 Corinthians (1:1) with Paul. He is prob. known to the Corinthians. If by “brother,” Paul means that Sosthenes is now a Christian, and if “our” means “one of you, belonging to both of us,” it may be that he is identical with 1 above, and that two former persecutors are now enjoying the fellowship of the Gospel. If they are not the same, this Sosthenes is otherwise unknown in the NT.

International Standard Bible Encyclopedia (1915)

Chief of the synagogue at Corinth (Ac 18:17). Possibly identical with the co-worker (afterward) of Paul mentioned in 1Co 1:1.