Piazza San Carlo, Square in central Turin, Italy

Piazza San Carlo is a rectangular plaza in central Turin lined with continuous arcaded passages on all sides. Two identical churches face inward from the southern end, while the space is anchored by an equestrian statue at its center.

Carlo di Castellamonte designed the square and the new Contrada Nuova (today's via Roma) in 1617, after Turin became the Savoy capital in 1563. Construction ran from 1618 to 1638, when Madama Cristina of France inaugurated it as Piazza Reale; the perimeter porticoes were added in 1643–1646. After 1650 it became Piazza d'Armi, used for troop movements between Piazza Castello and the Cittadella.

Turinese call the square "il salotto della città", the city's drawing room. The twin churches closing the south end are Santa Cristina, on the left, and San Carlo Borromeo, on the right, separated by the continuation of via Roma. The square hosts concerts, election rallies and live TV shows, and a plaque of 14 May 2019 commemorates the victims of the 2017 stampede.

The square is pedestrianised and crossed by via Roma, with entrances also from via Santa Teresa, via Maria Vittoria, via Giovanni Giolitti and via Vittorio Alfieri. Stairs connect it to the underground car park beneath. The Arcivescavado stop nearby is served by bus and tram lines 4, 11, 15, 55, 58 and 58/.

The bronze equestrian statue depicts Duke Emmanuel Philibert mounted on his horse in a heroic pose following his victory at the Battle of Saint-Quentin. It remains one of the oldest surviving monuments of its kind in Italy.