Theatre of Balbus was an ancient Roman structure in the Campus Martius of Rome.

Excavations of the theatre began in 1981 and are still ongoing, however, the main portion of the crypta finished in 2000.

Today what has been excavated can be seen at the Museo Nazionale Romano Crypta Balbi (National Museum of Rome), which is located at Via delle Botteghe Oscure, 31, (corner of Via M. Caetani).

A catalogue complied at the end of the 4th century recorded that the theatre's seating capacity was 11,510 persons.

[1] Currently, remains of the theater are preserved, showcasing 'opus quadratum' and 'opus reticulatum' construction techniques in the lower part of the cavea.