Palazzo Tolomei, Gothic palace in Siena, Italy.

Palazzo Tolomei is a Gothic palace located on Via Banchi di Sopra in Siena. Its stone facade displays double lancet windows and trefoil decorations across the upper stories in medieval style.

Built between 1270 and 1275, the palace served as the first permanent center of Siena's commune government during the Guelph period. The seat of power later moved when Palazzo Pubblico was established as the city's main administrative building.

Pia Tolomei, a thirteenth-century member of the family, was supposedly murdered in 1295 by her Guelph husband from the Maremma so he could remarry. Dante placed her in Purgatory, where she says: "Siena made me, but the Maremma unmade me." Donizetti later made her the subject of his opera Pia de' Tolomei.

The palace now houses the main branch of a bank, so access inside is limited to banking hours. Visitors can view the exterior architecture and the medieval column in front anytime, but interior access depends on business operations.

In front of the palace stands a column crowned with a Roman she-wolf, the emblem of Siena. The Tolomei family also produced Saint Bernardo Tolomei and the Blessed Nera Tolomei, both commemorated on the facade of the nearby church of San Cristoforo.