(b. 1512, Perugia, d. 1572, Perugia)
Italian architect. He studied drawing for civil and military architecture under the direction of Giovanni Battista Caporali. He became the leading mid-sixteenth-century architect in Genoa and Milan.
His first important building was Santa Maria Assunta in Carignano, Genoa, clearly based on Bramante's scheme for San Pietro in Rome. His domestic architecture, especially the Villa Cambiaso of 1548, has elements derived from the Palazzo Farnese in Rome. In Genoa he was involved in the lay-out of the streets and the restoration of the city walls, as well as being responsible for many of its impressive palazzi. In 1550 the Doge of Genoa ordered the construction of the Strada Nuova, which was laid out by Alessi, and lined with palaces: it was the first planned street of independent blocks of the period, each designed by a different architect, but with an overall control of certain architectural features, heights, and scale to ensure a degree of harmony. These palaces became internationally known after the publication of Rubens's Palazzi di Genova.
He was active in other Italian cities, including in Ferrara, Bologna, Naples and Milan. His enormous Palazzo Marino (1557) in Milan was richly treated on its elevations, and its cortile was a fine example of Mannerist decoration. His Churches of Santi Barnaba e Paolo (1561) and Santa Maria presso San Celso (1568), both in Milan, deserve note, the former for the distinct divisions between nave, presbytery, and choir, and the latter for its size and decorations, completed by Martino Bassi after Alessi's death.
Alessi designed churches and palaces also in France, Germany and Flanders. He produced designs for El Escorial in Spain, but age and health prevented him from carrying them out.