The Imperial Bank of Persia (Persian: بانک شاهنشاهی ایران‎, romanized: Bânk-e Šâhanšâhi-ye Irân), sometimes transcribed as Bank Shahi, was a British bank that played a central role in the financial history of late Qajar Iran, known in English at the time as Persia. The bank was legally established in London and subject to British law, with the bulk of its operations based in Tehran under a concession initially granted by the Qajar government to Paul Julius Reuter. It served as the country's main bank of issue until that role was transferred to Bank Melli Iran in 1932, and introduced European financial practices to a country in which they were previously unknown.

Following political changes in Pahlavi Iran it was renamed the Imperial Bank of Iran in 1935, then the British Bank of Iran and the Middle East in 1949 following expansion into other Middle Eastern countries. In 1952, its operations in Iran were terminated, with some of its former business restructured as Bank Bazargani. The remaining activity outside Iran was renamed British Bank of the Middle East (BBME), which in 1959 was purchased by HSBC and in 1999 was renamed HSBC Bank Middle East. Bank Bazargani in turn was reorganized in 1979 following the Iranian Revolution, to become the nucleus of Bank Tejarat.

Nineteenth-century Iran has been described as "one of the most backward countries in the world". As usury was forbidden under Islam, the traditional money lenders in Iran were mainly Jewish money-changers or sarrafs. The only form of money in circulation was gold and silver coins. A first attempt to create a modern European-style bank was the Oriental Bank Corporation, a British venture established in 1845 but which did not survive long. A successor entity, the New Oriental Bank Corporation, opened in 1884 but suspended its operations after a year. The New Oriental Bank Corporation (Bank Jadid Sharq) was again established in 1888 and opened branches in Tehran, Tabriz, Rasht, Mashhad, Isfahan, Shiraz, and Bushehr.

Paul Julius Reuter obtained the Reuter concession in 1872, entailing exclusive rights over many resources of Persia. While the main motivation for the concession was in order to develop railroads, it also gave Reuter a monopoly over banking for sixty years. The concession's leonine terms was resented by Iranian public opinion, alarmed Russia, and was also a concern for the British government which had been kept away from Reuter's negotiation until the last minute. Due to mounting pressure, the Shah cancelled the concession in 1873, invoking the fact that Reuter failed to initiate the railway project within 15 months as the text committed him to.

Reuter did not give up however, and the negotiation gained renewed momentum with support of both Mirza Malkam Khan, Persia's minister in London, and Henry Drummond Wolff, the UK's minister in Tehran. Paul Julius Reuter's son George traveled to Tehran in October 1888 to renegotiate the concession on changed terms, downplaying the railways component following a pledge by the Shah in 1887 that he would not engage in railway construction without Russian approval. Eventually, the modified concession was signed on 30 January 1889 with no provisions on railways. Although this new concession was not as vast as the first one, it still granted Reuter valuable control over Persian banking and mining. Reuter then secured a royal charter from the UK government on 2 September 1889, the first such document issued for an overseas British bank since 1864. The Imperial Bank subsequently had its shares publicly floated in London, and started operations by opening its first branch in Tehran in December 1889. On the basis of the concession's terms, the operations of the New Oriental Bank were transferred to the Imperial Bank. The Imperial Bank's first banknotes were issued in 1890, ranging from 1 toman to 1,000 tomans. The oldest known was dated 25 October 1890.

Between 1890 and 1932, the Imperial Bank operated as the only bank of issue in Iran. It was dominant in providing modern financial services in Iran, but it was not alone on that market. To start with, the traditional moneylenders continued to dominate the field for some time after the Imperial Bank's arrival due to greater loan flexibility and cultural ties. In 1890, the Loan and Discount Bank of Persia was established to keep British financial influence in check, even though it never appeared to make profits in its subsequent three decades of operations. In 1907, the Anglo-Russian Convention, which split Iran into Russian and British spheres of influence, assigned to the Russian Loan and Discount Bank the revenues from the amortization of Persian debts in northern Iran, and the same for the British Imperial Bank in southern Iran.

The bank was initially funded mostly by Glyn, Mills & Co., J. Henry Schröder & Co. and David Sassoon & Co. Sir William Keswick was its first chairman. Its first chief executive ("chief manager") was Joseph Rabino, born in London to an Italian father and thus viewed in London as a bit of an outsider. Rabino served eighteen years in Persia and was instrumental in building up the bank's reputation. The Imperial Bank did not employ locals as managers, in contrast with the Imperial Ottoman Bank, but nevertheless played a role in educating modern business elites in Iran.

At the time, Persians were wary of giving up silver and gold coins for paper notes. Rabino ordered all branches to keep enough silver coins to be able to redeem paper notes for silver on demand. However bank runs did occur in the early years of the bank, sometimes instigated by Russian agents. The bank issued only small notes in the early years to be able to redeem the notes for silver even in the remote areas. With the protection of Persian soldiers, the bank supplied even remote branches with enough silver coins. The bank relied on support from general Albert Houtum-Schindler in Tehran who was, like Reuter, a British subject of German origin. Schindler lived in Persia for many years and was the most informed member of the European community in Persia at the time; Henry Drummond Wolff tried unsuccessfully to persuade the foreign office to engage him as a member of Legation staff, and Reuter employed him instead.^{[citation needed]}