Palazzo Valguarnera-Gangi is the large ancestral townhouse first of the Princes Valguarnera and then of the Princes Gangi, situated in the Piazza Croce dei Vespri, Palermo, Sicily. The house was constructed in several phases during the 18th century and completed circa 1780.

The palace is designed in the Baroque style, although its ornamentation is of a more severe form than that which is generally accepted as Sicilian Baroque. The tall windows of the piano nobile are decorated with alternating pointed and segmented pediments, while the windows of the lower and upper floors are much smaller, almost cell like, indicating the lower status of the rooms they house. In this way the architecture could be said to be more Renaissance than Baroque.

In 1750 the interior was created in true Sicilian Baroque style by Marianna Valguarnera, with special furniture in the very ornate style being created by local craftsmen. The creation of the house took so long that the Baroque style passed from fashion in favour of the neoclassical style, and it was during this era that the large circular and domed dining room was created with its painted panels in the dome by Giuseppe Velasco.
In 1963 the palazzo, and most memorably its ballroom, were the setting for Luchino Visconti's film' Il Gattopardo (The Leopard).

Today, while the famous ballroom may be hired for functions, the remainder of the house remains a private residence.