The Indianapolis Symphony Orchestra (ISO) is a major American orchestra based in Indianapolis, Indiana. The largest performing arts organization in Indiana, the orchestra was founded in 1930 and is based at the Hilbert Circle Theatre in downtown Indianapolis on Monument Circle.

The Hilbert Circle Theatre, originally called the Circle Theatre, is in Indianapolis, Indiana, on Monument Circle in the Washington Street-Monument Circle Historic District. It was originally built in 1916 as a "deluxe movie palace" and now is the home of the Indianapolis Symphony Orchestra.