GUASTALLA, a town and episcopal see of Emilia, Italy, province of Reggio, 18 m. N. by rail of Reggio, on the south bank of the Po, 79 ft. above sea-level. It is also connected by rail with Parma and Mantua (via Suzzara). Pop. (town) ; 13,244 (commune). The cathedral dates from the loth century. Guastalla was founded by the Lombards in the 7th century. In 1307 it was seized by Giberto da Correggio of Parma. In 1403 it passed to Guido Torello, cousin of Filippo Maria Visconti of Milan. In 1539 it was sold by the last female descendant of the Torelli to Ferrante Gonzaga. In 1621 it was made the seat of a duchy, but in 1748 it was added to the duchies of Parma and Piacenza.