If Machiavelli was a committed republican, as the dominant interpretations suggest, then why did he heap praise on an oligarchic creditor government that ran the city of Genoa in the fifteenth century? In the Florentine Histories, Machiavelli offers a curious encomium to a remarkable oligarchic institution in Genoa: the Bank of Saint George (Casa di San Giorgio). A creditor association and oldest chartered bank in the world, San Giorgio owned Genoa’s public debt. In return for the credit it extended to the commune, the Casa exercised a striking degree of fiscal, judicial, political, and even military power. This politically unaccountable creditor government with its discretionary powers would seem to violate Machiavelli’s commitments to institutionalized forms of sharing power. This article offers a sustained analysis and historical contextualization of Machiavelli’s remarks about San Giorgio. Drawing on historical research on public debt in Renaissance Italy, I put forward a new hypothesis to explain Machiavelli’s praise for the institution.