In architecture, an exedra, a word from the Greek exedra, "meeting room with seats"[1]​ is, generally, an open construction, with a semicircular plan, with seats and backrests fixed on the inside of the curve. Exedras are often placed on the façade of a palace, but designed as an opening in the internal wall. Open space can also be an arena.[1]​.

The original Greek meaning (ἐξέδρα, from ἐξ, "outside" and έδρα, "seat", a seat "Seat (furniture)") on the outside of the door) has been applied to a room that opens and is surrounded by tall, curved stone benches: an open environment intended to serve as a place of meeting and philosophical conversation. An exedra can also stand out from an empty, curved space within a colonnade perhaps with semicircular seats. In the Greek and Roman house it was open to the peristyle.[1]​.

The exedra achieved special popularity in Roman architecture during the century with Nero's architects, who incorporated the exedra throughout the planning of their Domus Aurea, enriching the volumes of the rooms, something very pretentious, since no one had seen domes and exedra in a home.

The exedra was widely adopted by the Romans to consolidate itself in later historical periods. In the early Christian basilica, the exedra has benches with a semicircular profile raised by steps. It is consolidated in Byzantine architecture and Romanesque architecture, for example, in churches, the choir that surrounds the presbytery "Presbytery (architecture)").[1]​.