located on the Via del Quirinale and facing into the Piazza del Quirinale, was built in 1573 by Pope Gregory XIII as a papal summer residence. It was also used as the location for papal conclaves in 1823, 1829, 1831, and 1846. It served as a papal residence and housed the central offices responsible for the civil government of the Papal States until 1870. In September, 1870, what was left of the Papal States was overthrown. About five months later, in 1871, Rome became the capital of the new Kingdom of Italy. The palace became the official royal residence of the Kings of Italy, though some monarchs, notably King Victor Emmanuel III (reigned 1900-1946) actually lived in a private residence elsewhere, the Quirinale being used simply as an office and for state functions. The monarchy was abolished in 1946 and the Palace became the official residence and workplace for the Presidents of the Italian Republic. Some, still, declined the Colle residence and kept their usual Roman residence: for example, Sandro Pertini preferred his old flat near the Trevi fountain.

The façade was designed by Domenico Fontana. Its 'Great Chapel' was designed by Carlo Maderno. It contains frescos by Guido Reni, but the most famous fresco is the Blessing Christ by Melozzo da Forlì, placed over the stairs. Its grounds include a famous set of gardens laid out in the eighteenth century.