Vicenza, city, episcopal see, Veneto region, northern Italy, traversed by the Bacchiglione and Retrone rivers, at the eastern end of the valley between the Monti Lessini and the Monti Berici (which connects Lombardy with Veneto), northwest of Padua. Originally a settlement of the Ligurians or Veneti, it became the Roman Vicetia and, after the barbarian invasions, the seat of a Lombard duchy. In 1164 it formed part of the Veronese League against Frederick I Barbarossa and continued through the 13th century to struggle against the imperial power and local tyrant lords. It was ruled by the Scaligers from 1311 until it passed to the Visconti (1387) and in 1404 to Venice, whose fortunes it afterward shared. It suffered widespread destruction in World War II but has been largely restored.

Once surrounded by 13th-century walls, Vicenza is a compact city, famous as the home of the 16th-century architect Andrea Palladio and his successor Vincenzo Scamozzi, who enriched it with numerous buildings. The most notable Palladian structures are the Basilica (1549–1614); the Loggia del Capitanio (1571); the Teatro Olimpico (1580–85), Palladio’s last work, finished by Scamozzi; and the Villa Rotonda (1553–89), also completed by Scamozzi (1599). Palladio’s Palazzo Chiericati (1551–57) houses the city art museum, which contains works by northern Italian painters. Earlier churches include the Gothic cathedral (13th century, rebuilt since 1944), Santa Corona (1260, restored), San Lorenzo (13th century), and SS. Felice e Fortunato (nucleus 4th century, with major restorations of the 10th–12th century). The Basilica of Monte Berico (rebuilt 1687–1702) and the Villa Valmarana (1669) stand outside the city.

The economic and communications centre of its province, Vicenza has engineering, food-processing, chemical, textile, and timber industries. Vicenza was designated a UNESCO World Heritage site in 1994. Pop. (2008 est.) mun., 114,108.