The Minor Basilica of St. Lawrence in Damaso (Basilica Minore di San Lorenzo in Damaso) or simply San Lorenzo in Damaso is a parish and titular church in central Rome, Italy that is dedicated to St. Lawrence, deacon and martyr. It is incorporated into the Palazzo della Cancelleria, which enjoys the extraterritoriality of the Holy See.

Archaeological evidence suggests the site, like those of many churches in Rome, may have formerly housed a pagan temple. The first documentary evidence of a church at this site is the reference in the synod of Pope Symmachus of AD 499 of a Titulus Damasi. According to tradition, in the AD 380s a basilica church was erected by Pope Damasus I in his own residence. This church is one of many in Rome dedicated to St. Lawrence, including the more ancient and then extra-urban Basilica di San Lorenzo Fuori le Mura, that was rebuilt by the same Pope Damasus I. The original basilica of San Lorenzo in Damaso was demolished by Cardinal Raffaele Riario, a nephew of Pope Sixtus IV who commissioned the imposing Renaissance-style Palazzo della Cancelleria (1489–1513). The palace was built of spolia and stone from nearby ancient Roman buildings, including the Colosseum, and enveloped the new basilica of San Lorenzo in Damaso under the right wing; the entrance is located at Number 1, Piazza della Cancelleria, on the right flank of the façade.

The architect of the basilica, like that of the Palace of the Chancellery, is unknown. The design of the Palace has been attributed to Francesco di Giorgio Martini and Baccio Pontelli, while Filippo Titi suggests Donato Bramante and other authors have cited Giuliano da Sangallo and Andrea Bregno. Titi also independently attributed reconstruction of the basilica to Bramante. The last restoration was necessary after a fire damaged the basilica in 1944.

The inscriptions in the basilica are valuable illustrations of the history of the Roman Catholic Church, and were collected and published by Vincenzo Forcella.

The Cardinal Priest of the Titulus S. Laurentii in Damaso is Antonio Rouco Varela, former Archbishop of Madrid, Spain.

The interior decoration was begun by commissions of the resident of the Palace, Cardinal Alessandro Farnese, in the late 16th century. Cavaliere d'Arpino painted the walls of the right counter-façade. The main altar hosts the painting of Saints and Coronation of St. Mary by Federico Zuccari. Below the altar are the relics of Pope Eutychian and Pope Damasus I. To the left of the altar is a copy of a statue of St. Hippolytus of Rome; the original is a restored antique statue in the Vatican Library. Tradition holds that St. Lawrence instigated the conversion of St. Hippolytus to the Catholic Faith. This copy was commissioned for the basilica by Cardinal Pietro Ottoboni. Vignola designed the portal. Immediately to the right of the entrance is the memorial to Alessandro Valtrini, a minister of Pope Urban VIII, that Gian Lorenzo Bernini designed in 1639. The second vestibule has statues of St. Francis Xavier and St. Charles Borromeo by Stefano Maderno.

To the right of the entrance is a chapel designed by Nicola Salvi and commissioned by Cardinal Tommaso Ruffo in the late 18th century. The ceiling is frescoed with Glory of San Nicola by Corrado Giaquinto, and the altarpiece of Virgin with Sts. Philip Neri and Nicolò was painted by Sebastiano Conca. To the left of the entrance is the Chapel of the Blessed Sacrament, which was commissioned by Cardinal Ottoboni and frescoed by Andrea Casali. The altarpiece is the Last Supper by Vincenzo Berrettini.

Inside the basilica, the first chapel to the right of the nave has a 19th-century monument to Prince Camillo Massimi and his wife, by Filippo Gnaccarini and Pietro Tenerani, respectively.

The second chapel to the right has the tomb of Pellegrino Rossi, the last minister of the Papal States under Bl. Pope Pius IX, by Pietro Tenerani. His murder in 1848 in the adjacent Palace was one of the events that led to the ensconcement of the Pope in the Vatican City and the annexation of the Papal States to the Kingdom of Italy.

The first chapel to the left has the tomb and funerary monument of Cardinal Ludovico Trevisan, Patriarch of Aquileia, with a recumbent statue by Paolo Romano.

The second chapel to the left contains the tomb of Fra Annibal Caro (1566) by Giovanni Antonio Dosio.

A chapel near the sacristy has an altarpiece depicting the Madonna delle Gioie by Nicolò Circignani, denominated "il Pomarancio", and two silver statues of St. Lawrence and St. Damaso by Ciro Ferri.

A further chapel is dedicated to the Sacred Heart of the Agonizing Jesus, and contains a portrait of Pope Leo XIII proclaiming the statutes of the Pious Union of the Sacred Heart of Jesus by the chapel's 19th century architect Vincenzo De Rossi Re. The founding of this fraternity was celebrated in the basilica in 1883.

The Chapel of the Santissima Concezione was completed and frescoed (1635-8) by a young Pietro da Cortona. Other works include the monument of Cardinal Trevisan (1505).

• Hüls, Rudolf (1977). Kardinal, Klerus und Kirchen Roms: 1049–1130, Tübingen: Max Niemeyer 1977. (in German)
• Pietro da Cortona, A Design for a Quarantore at San Lorenzo in Damaso, c. 1632

• Lucentini, M. (31 December 2012). The Rome Guide: Step by Step through History's Greatest City. Interlink. ISBN 9781623710088.

Media related to San Lorenzo in Damaso at Wikimedia Commons

Preceded by Santi Giovanni e Paolo al Celio

Landmarks of Rome San Lorenzo in Damaso

Succeeded by San Lorenzo in Lucina