Palazzo Guasco Gallarati di Bisio, Noble palace in Alessandria, Italy.

Palazzo Guasco Gallarati di Bisio stands on Via dei Guasco in Alessandria. Its present layout dates from the 18th-century remodelling commissioned by Marquis Lodovico Guasco-Gallarati di Solero (1723–1784). The right wing houses provincial offices, the Biblioteca provinciale di Editoria locale, the Istituto per la storia della Resistenza and the Galleria d'arte moderna Carlo Carrà; the left wing remains private.

The palace's history reaches back to the first centuries after Alessandria's founding, and its present form is 18th-century, the result of rebuilding commissioned by Marquis Lodovico Guasco-Gallarati di Solero (1723-1784). On his death on 20 March 1784 it passed to Paolo Guasco di Bisio e Francavilla, then in 1800 to his son Francesco, an office-holder under French rule, and in 1847 to Marquis Francesco Guasco Gallarati di Bisio (1847-1926).

The palace carries the name of the Guasco Gallarati family, who held it for centuries; Marquis Lodovico Guasco-Gallarati di Solero (1723-1784) commissioned the 18th-century remodelling. In 1729 Marquis Filippo Guasco obtained royal patents from Vittorio Amedeo II to run a small public theatre inside the building, the city's first, and had the central first-row box decorated with the Savoy coat of arms.

The palace stands on Via dei Guasco, the street that carries the family's name. Its right wing holds the Province of Alessandria's economy and development directorate, the provincial library of local publishing, the Istituto per la storia della Resistenza and the Carlo Carrà modern art gallery; the left wing is private property. Some halls keeping their 18th-century structure await restoration, so expect parts to be closed.

In 1729, Filippo Guasco established a theater within the palace that became the city's primary venue for opera performances. This private theater served as a cultural hub until 1766 and shaped the artistic life of Alessandria.