Heidegger's Bible Handbook: 1 Thessalonians: Subscript
4. It appears to have been written, not at Athens, but at Corinth.
That the Epistle was written at Athens, the common subscription affirms.Yet in Claromontanus and the Syriac Codex, no mention is made of Athens; but it is thus simply subscribed: Ἐπληρωθη πρὸςΘεσσαλονικεῖς πρώτη, the first to the Thessalonians is finished. That it was written, not at Athens, but rather at Corinth, where, with Athens left behind, Paul betook himself, as Luke testifies, Acts 18:11, is credibly argued by Beza, and Baronius following him, out of the history of the journey of Saint Paul and Timothy, especially out of Acts 18:5.