This building is part of the headquarter of Banca Monte dei Paschi of Siena. It was built in 1473 by the architect Giuliano da Maiano on commission of a Sienese merchant who wanted to pay tribute to the considerable commercial power acquired by his family: Ambrogio di Nanni Spannocchi.
The architectural canons of the palace are inspired by classical art with a new feature: on the upper part the northern facade is adorned with numerous carved heads depicting ancient Roman emperors and illustrious people. At the center, on the same facade, is affixed the ancient coat of arms of the bank. Inside the palace there was a courtyard surrounded by a loggia that in the 70s was remodeled to accommodate the bank tellers for the public.
Before Giuseppe Partini's restoration in 1880, there was a hanging garden on the side overlooking Piazza Salimbeni.
Palazzo Spannocchi has a strong resemblance to Palazzo Medici Riccardi in Florence.