The Church of San Cesareo de Appia is located in Rome , more precisely in the Celio district, near the Porta di San Sebastiano.

The church has ancient origins: it dates back to the 8th century and was built on the remains of pre-existing Roman structures, which today can be observed in the basement (remains of a mosaic floor, with marine scenes from the 2nd century AD). During the sixteenth century it also appeared with the name of San Cesareo in Palatio , creating a lot of confusion with the homonymous church in the Campitelli district.

Over the centuries the Church of San Cesareo de Appia changed hands several times and was renovated several times: in the 14th century it was entrusted to the Crociferi who founded a hospital there. The Benedictine nuns followed and in the 15th century it was entrusted to the care of the nearby Church of San Sisto Vecchio and then to those of the Church of Santi Nereo and Achilleo; it was completely restored in the 16th century by the Cavalier d'Arpino, and then entrusted to the Somascan Fathers.

On this occasion, the 13th-century mosaics and other architectural furnishings found in the transept of the Basilica of San Giovanni in Laterano, which were being renovated at that time, were transferred here.

The Church of San Cesareo de Appia has a very sober facade with an access door preceded by a porch with granite columns. The interior has a single nave. On the side walls, between the windows, there are mosaics by Cavalier d'Arpino , with scenes from the life of San Cesareo. In the apse a mosaic depicting God the Father among the angels . The altar, the ambo, the chair, the barriers of the presbytery are architectural elements that belonged to the Basilica of San Giovanni : mostly they are composed of heterogeneous elements that date back to the thirteenth century.