Banca Monte dei Paschi di Siena in the context of Mount of piety

Siena (/siˈɛnə/ see-EN-ə, Italian: [ˈsjɛːna, ˈsjeːna] ; traditionally spelled Sienna in English; Latin: Saena Iulia) is a city in Tuscany, in Central Italy, and the capital of the province of Siena. With a population of 52,991, it is the 12th-largest city in the region as of 2025.

The city is historically linked to commercial and banking activities, having been a major banking centre until the 13th and 14th centuries. Siena is also home to the oldest bank in the world, the Monte dei Paschi, which has been operating continuously since 1472 (553 years ago) (1472). Several significant Mediaeval and Renaissance painters were born and worked in Siena, among them Duccio di Buoninsegna, Ambrogio Lorenzetti, Simone Martini and Sassetta, and influenced the course of Italian and European art. The University of Siena, originally called Studium Senese, was founded in 1240, making it one of the oldest universities in continuous operation in the world.

A financial institution is an organization that provides financial services related to the management and transfer of money and other financial assets, and is broadly classified into banking institutions and non-bank financial institutions.

This list of the oldest banks includes financial institutions in continuous operation, operating with the same legal identity without interruption since their establishment until the present time.

The world's oldest bank is Banca Monte dei Paschi di Siena, while the world's oldest merchant bank is Berenberg Bank. Banca Monte dei Paschi di Siena was founded in its present form in 1624, but traces its history to a mount of piety founded in 1472. The Berenberg company was founded in 1590 and has operated continuously ever since with the same family as owners or major co-owners. Banca Monte dei Paschi di Siena is today a large Italian retail bank, while Berenberg Bank is primarily involved in investment banking and private banking for wealthy customers; in any event Berenberg Bank is the world's oldest merchant bank or investment bank. The world's oldest central bank is the Sveriges Riksbank, which was founded in 1668. Banco di Napoli, which was absorbed by different entities between 2002–2018, had origins dating back to 1539, and until its absorption was likely the oldest bank worldwide in continuous operation; some scholars posit that its origins may be dated back to 1463.

The history of banking began with the first prototype banks, that is, the merchants of the world, who gave grain loans to farmers and traders who carried goods between cities. This was around 2000 BCE in Assyria, India and Sumer. Later, in ancient Greece and during the Roman Empire, lenders based in temples gave loans, while accepting deposits and performing the change of money. Archaeological findings from this period in ancient China and India also include evidence of money lending.

Many scholars trace the historical roots of the modern banking system to medieval and Renaissance Italy, particularly the affluent cities of Florence, Venice and Genoa. The Bardi and Peruzzi families dominated banking in 14th century Florence, establishing branches in many other parts of Europe. The most famous Italian bank was the Medici Bank, established by Giovanni Medici in 1397. The oldest bank still in existence is Banca Monte dei Paschi di Siena, headquartered in Siena, Italy, which has been operating continuously since 1472. Until the end of 2002, the oldest bank still in operation was the Banco di Napoli headquartered in Naples, Italy, which had been operating since 1463.