Also based on a Michelangelo architectural plan, this compact gallery is well endowed in classical sculpture and paintings. Highlights include the small 1st-century-BC bronze Lo Spinario, a Greek statue of a little boy picking a thorn from his foot; the Lupa Capitolina (Capitoline Wolf), a rare Etruscan bronze statue probably dating from the 5th century BC; and (in the entrance courtyard), the massive head, hands, foot and kneecap from a colossal statue of Constantine the Great. The palace also contains a Pinacoteca (Picture Gallery) with paintings mainly from the 16th and 17th centuries - highlights include: Caravaggio's Fortune-Teller and his curious John the Baptist; The Holy Family, by Dosso Dossi; Romulus and Remus, by Rubens; and Titian's Baptism of Christ.

The Capitolium or Capitoline Hill , between the Forum and the Campus Martius, is one of the Seven Hills of Rome. The hill was earlier known as Mons Saturnius, dedicated to the god Saturn. The word Capitolium first referred to the Temple of Jupiter Optimus Maximus which was located on the hill; however, the meaning evolved to refer to the whole hill and even other temples of Jupiter on other hills. In an etymological myth, ancient sources connect the name to caput because of a tale that stated that when the foundations for the temple were being laid, a man's head was found. The Capitolium was regarded by the Romans as indestructible, and was adopted as a symbol of eternity. The word Capitolium is a precursor to the English word capitol, and Capitol Hill in Washington, D.C. is widely assumed to be named after the Capitoline Hill.