Sant'Agnese in Agone is a 17th-century Baroque church in Rome, Italy. It faces onto the Piazza Navona, one of the main urban spaces in the historic centre of the city and the site where the Early Christian Saint Agnes was martyred in the ancient Stadium of Domitian. Construction began in 1652 under the architects Girolamo Rainaldi and his son Carlo Rainaldi. After numerous quarrels, the other main architect involved was Francesco Borromini.

The Stadium of Domitian, also known as the Circus Agonalis, was located to the north of the Campus Martius in Rome, Italy. The Stadium was commissioned around AD 80 by Emperor Titus Flavius Domitianus as a gift to the people of Rome and was used almost entirely for athletic contests. In Christian tradition, Agnes of Rome was martyred there.