Carlo Fontana

Carlo Fontana (1634/1638–1714) was an Italian architect originating from today's Canton Ticino. He was partly responsible for the classicizing direction taken by Late Baroque Roman architecture.

There seems to be no proof that he belonged to the family of famous architects of the same name, which included Domenico Fontana, although he is sometimes called his great-nephew.

Born in Brusato, near Como (now part of the town of Novazzano in Canton Ticino, Switzerland), Fontana went to Rome before 1655. He became a draughtsman for the architectural plans of Pietro da Cortona, Carlo Rainaldi, and Gian Lorenzo Bernini. Bernini employed him for nearly a decade in diverse projects. He finished Bernini's Palazzo Ludovisi, which had been started for Cardinal Ludovico Ludovisi, nephew of Pope Gregory XV; and modified Bernini's plan with the addition of a bell gable above the main entrance.

His first independent project may be the church of San Biagio in Campitelli, completed by 1665. After a fire during the night of Good Friday in 1670 destroyed the roof and part of the interior of the Basilica Cattedrale di Santa Margherita in Montefiascone, the repair and completion of the construction was entrusted to Fontana. Around that time, he also designed the Ginetti Chapel in Sant'Andrea della Valle.

The façade at San Marcello al Corso (1682–83) is described as one of his most successful works. Around 1700, he and his son Francesco designed a new Baroque interior for Santi Apostoli. Innocent XII commissioned Fontana to extend the Ospizio Apostolico di San Michele complex, organized around its church. The first chapel in the south aisle of St. Peter's Basilica is the baptistry, commissioned by Pope Innocent XII and designed by Fontana.

At the request of Clement XI he built the public oil depots (Olearie Papali) within the ruins of the Baths of Diocletian He also built a new granary.

In 1702 Fontana restored the façade of Santa Maria in Trastevere, replacing the ancient porch with a sloping tiled roof. He also restored the octagonal fountain in the piazza in front of the church in the Piazza di Santa Maria in Trastevere. In 1708 he designed the Biblioteca Casanatense at Santa Maria sopra Minerva.

Fontana mainly worked in Rome, assisted by his nephews Girolamo and Francesco Fontana (1668–1708), but he sent a model for the Fulda Cathedral, and others to Vienna for the royal stables. Among his other foreign works were the designs for the Sanctuary of Loyola in Spain, where Saint Ignatius of Loyola, the founder of the Jesuit Order, was born. This grandiose basilica was a major influence on the baroque architecture of the New World.