Banking in Switzerland dates to the early 18th century through Switzerland's merchant trade and over the centuries has grown into a complex and regulated international industry. Banking is seen as very emblematic of Switzerland and the country has been one of the largest, if not largest, offshore financial centers and tax havens in the world since the mid-20th century, with a long history of banking secrecy, security and client confidentiality reaching back to the early 1700s. Starting as a way to protect wealthy European banking interests, Swiss banking secrecy was codified in 1934 with the passage of a landmark federal law, the Federal Act on Banks and Savings Banks. These laws were used to protect assets of persons being persecuted by Nazi authorities but have also been used by people and institutions seeking to illegally evade taxes, hide assets, or to commit other financial crime.

Controversial protection of foreign accounts and assets during World War II sparked a series of proposed financial regulations seeking to limit bank secrecy, but with little resulting action. Despite various international efforts to roll back banking secrecy laws in the country which were largely minimized or reverted by Swiss social and political forces, in 2017 Switzerland agreed to "automatic exchange of information" (AEOI) with foreign governments and their revenue services regarding information of depositors not resident in Switzerland. This constituted de facto the end of Swiss banking secrecy for depositors who were not Swiss residents. Furthermore, after Switzerland ratified the Foreign Account Tax Compliance Act agreement with the United States, because of concerns regarding their tax liability (the U.S. taxes its citizens regardless of whether they are resident in the U.S. or not) some Swiss banks have gone so far as to close accounts held by US citizens, and to ban the opening of new accounts by US citizens and by dual US-Swiss citizens, including those deemed lawful permanent Swiss residents. Thus banking secrecy remains in force only for those residing in and solely taxable in Switzerland.

Disclosing client information has been considered by Switzerland a criminal offence since the early 1900s. Employees working in Switzerland and at Swiss banks abroad have "long adhered to an unwritten code similar to that observed by doctors or priests". Since 1934 Swiss banking secrecy laws have been violated to a major extent by only four people, namely: Christoph Meili (1997), Bradley Birkenfeld (2007), Rudolf Elmer (2011) and Hervé Falciani (2014).^{[citation needed]}

The Swiss Bankers Association (SBA) estimated in 2018 that Swiss banks held US$6.5 trillion in assets or 25% of all global cross-border assets. Switzerland's main lingual hubs, Geneva (for French), Lugano (for Italian), and Zürich (for German) service the different geographical markets. It currently ranks number two behind the United States and on par with Singapore in the Financial Secrecy Index. The banks are regulated by the Swiss Financial Market Supervisory Authority (FINMA) and the Swiss National Bank (SNB) which derives its authority from a series of federal statutes. Banking in Switzerland has historically played, and still continues to play, a dominant role in the Swiss economy and society. According to the Organisation for Economic Co-operation and Development (OECD), total banking assets amount to 467% of total gross domestic product. Banking in Switzerland has been portrayed, with varying degrees of accuracy, in overall popular culture and television shows.

Switzerland's credibility as a banking centre was hurt in 2023 after the collapse of Credit Suisse, one of the largest Swiss banks, which was subsequently acquired by its Swiss competitor UBS. However, the rapid action taken by the Federal Council, the Swiss National Bank, and FINMA helped to minimise further damage.

Bank secrecy in the Swiss region can be traced to the Great Council of Geneva, which outlawed the disclosure of information about the European upper class in 1713. During the 1780s, Swiss bank accounts began insuring deposits, which contributed to their reputation for financial security. In 1815, the Congress of Vienna formally established Switzerland's international neutrality, which led to a large capital influx. The wealthy, landlocked Switzerland saw banking secrecy as a way to build an empire similar to that of France, Spain, and the United Kingdom. Swiss historian Sébastian Guex notes in The Origins of Secret Swiss Bank Accounts:

This is what the Swiss bourgeoisie are thinking: "That's our future. We will play on the contradictions between the European powers and, protected by the shield of our neutrality, our arm will be industry and finance."

After a small scale civil war in the 1840s between the Swiss cantons, the Swiss Federation was founded in 1848. The formation of the state, through a direct democracy, contributed to the political stability needed for banking secrecy. The mountainous terrain of Switzerland provided a natural environment in which to excavate underground vaults for storage of gold and diamonds. In the 1910s, during World War I, Swiss bankers traveled to France to advertise the country's banking secrecy. According to Sébastien Guex, the banks printed "brochures, circulars, personalised letters, and advertising in newspapers, and sent representatives who approached their clientele in person". The war's contribution to political and economic instability sparked a rapid capital movement into Switzerland. As France and Germany introduced progressive income and inheritance taxes for the first time, taxing greater wealth at higher rates to finance the war, wealthy clients moved their holdings into Swiss accounts to avoid taxation. The French banked in Geneva, the Italians in Lugano, and the Germans in Zürich.