The Odeon building has the shape of a small theatre with a stage building, seating places, and an orchestra. It had two functional uses. First, it was used as a Bouleuterion for the meetings of the Boule or the Senate. The second function was the Odeum – a concert hall for performances. It was constructed in the 2nd century AD by the order of Publius Vedius Antonius and his wife Flavia Paiana, two wealthy citizens of Ephesus.
It had a capacity of 1500 spectators and had 3 doors opening from the stage to the podium. The podium was narrow and one meter higher than the orchestra section. The stage building was two-storeyed and embellished with columns. The podium in front of the stage building and some parts of the seating have been restored. Archeologists think that it may have had a roof, since there is no drainage system.