The Bouleuterion of Sagalassos was built at the beginning of the 1st century BC on a natural terrace west of the upper Agora. It had a strong symbolic meaning for the inhabitants of Sagalassos. It was a point of reference for many later buildings and monuments of the upper part of the city that followed its orientation.
This building is proof that Sagalassos had an elected and active council (bule) at that time. The institution was already old then: Sagalassos was from the 4th century B.C. a polis (city-state) according to the Greek model, with elected judges and written laws. This model continued in Roman times, although civil institutions were dominated by a few elite families who replaced democracy with oligarchy.

The rectangular limestone building itself was rather sober. Together with the 5 rows of seats on the south side, 8 rows on the west side and 5 rows in the east, it could accommodate 220 elected councillors. Like the Bouleuterion of Priene, it has a special feature. The cavea is not semicircular as usual, the seating steps are rectangular to each other.

A frieze on the outside of the monument showed weapons; on the front the busts of the god Ares and the goddess Athena were worked into the frieze. Inside the building, following a new and fashionable style in Pisidia at that time, semi-capitals in Corinthian style were used.
From 200 AD the Bouleuterion was no longer used and the city council probably met in the Odeon instead.