Carlo Rainaldi (4 May 1611 – 8 February 1691) was an Italian architect of the Baroque period. Born in Rome, Rainaldi was one of the leading architects of 17th century Rome, known for a certain grandeur in his designs. He worked at first with his father, Girolamo Rainaldi, a late Mannerist architect in Rome. After his father's death, he fully embraced the monumental Baroque style. He gained ascendancy in Rome when the Barberini papacy of Pope Urban VIII was replaced by that of the more austere Pamphilj papacy of Innocent X. His works include the façade of Sant'Andrea della Valle (1661-65), the twin churches of Santa Maria dei Miracoli and Santa Maria in Montesanto, and Santa Maria in Campitelli (1663-67), considered his finest work. He was unable to complete the facade of Sant'Agnese in Ago