Tagliolo Monferrato is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about southeast of Turin and about south of Alessandria. As of 31 December 2004, it had a population of 1,499 and an area of .
The municipality of Tagliolo Monferrato contains the frazioni (subdivisions, mainly villages and hamlets) Cherli, Grossi, Varo, Pessino, Caraffa, Gambina and Mongiardino.
Tagliolo Monferrato borders the following municipalities: Belforte Monferrato, Bosio, Casaleggio Boiro, Lerma, Ovada, Rossiglione, and Silvano d'Orba.