Rosignano Monferrato is a comune (municipality) in the Province of Alessandria in the Italian region Piedmont, located about east of Turin and about northwest of Alessandria. As of 31 December 2004, it had a population of 1,659 and an area of .
Rosignano Monferrato borders the following municipalities: Camagna Monferrato, Casale Monferrato, Cella Monte, Frassinello Monferrato, Ozzano Monferrato, San Giorgio Monferrato, and Terruggia.