Only mentioned in Acts 19:29,31. The ruins of this theatre at Ephesus still exist, and they show that it was a magnificent structure, capable of accommodating some 56,700 persons. It was the largest structure of the kind that ever existed. Theatres, as places of amusement, were unknown to the Jews.
These dictionary topics are from M.G. Easton M.A., D.D., Illustrated Bible Dictionary, Third Edition, published by Thomas Nelson, 1897. Public Domain, copy freely.
Easton, Matthew George. "Entry for 'Theatre'". "Easton's Bible Dictionary".