Trequanda is a comune (municipality) in the Province of Siena in the Italian region Tuscany, located about 70 kilometres (43 mi) southeast of Florence and about 30 kilometres (19 mi) southeast of Siena.

Trequanda borders the following municipalities: Asciano, Pienza, Rapolano Terme, San Giovanni d'Asso, Sinalunga and Torrita di Siena and consists of the following villages: Trequanda, Castelmuzio and Petroio.