The Church of Sant'Agnese in Agone represents a masterpiece of Roman Baroque. Located in the heart of Rome, it overlooks Piazza Navona, the site where, according to legend, the young Agnes was martyred during Diocletian's persecutions. The name of the square derives from "in Agone," from the Latin in agonis ("games"), as the square follows the perimeter of what was once the Stadium of Domitian, intended by the emperor for athletics.

The church was rebuilt in 1652 in Baroque style on the site of the ancient basilica dedicated to the martyr by Callixtus II, designed by Girolamo Rainaldi and commissioned by Pope Innocent X Pamphili, whose funerary monument is located inside the church. It was completed in 1653-1657 under the direction of Francesco Borromini, who partially modified the original design by creating a concave façade and further distancing the two bell towers to enhance the soaring dome.

The interior retains the Greek cross plan and is sumptuously decorated with precious marbles and extensive use of gilded stucco. The high altar was designed by Carlo Rainaldi and houses the marble altarpiece of the Holy Family by Domenico Guidi. Borromini extended the arms of the Greek cross with two side chapels.

The fresco in the dome is the work of Ciro Ferri and Sebastiano Corbellini and depicts Saint Agnes being introduced to the glory of Paradise. Another important painting is found on the vault of the sacristy and depicts the glory of Saint Agnes; it is Work by Paolo Gismondi.

The crypt, or Sacellum Infimum, is the only surviving part of the original church and is accessed from the chapel of Saint Agnes. Here, there is a marble relief by Alessandro Algardi, placed above the altar, depicting the miracle of the hair of Saint Agnes: according to legend, the young Agnes was exposed naked in the pillory because she was a Christian, but miraculously her hair covered her.