ICICI Bank Limited is an Indian multinational bank and financial services company headquartered in Mumbai with a registered office in Vadodara. It offers a wide range of banking and financial services for corporate and retail customers through various delivery channels and specialized subsidiaries in the areas of investment banking, life, non-life insurance, venture capital and asset management.

ICICI Bank has a network of 7,066 branches and 13,376 ATMs across India. It also has a presence in 11 countries. The bank has subsidiaries in the United Kingdom and Canada; branches in United States, Singapore, Bahrain, Hong Kong, Qatar, Oman, Dubai International Finance Centre, China and South Africa; as well as representative offices in United Arab Emirates, Bangladesh, Malaysia and Indonesia. The company's UK subsidiary has also established branches in Belgium and Germany. The Reserve Bank of India (RBI) has identified the State Bank of India, HDFC Bank, and ICICI Bank as domestic systemically important banks (D-SIBs), which are often referred to as banks that are "too big to fail".

The Industrial Credit and Investment Corporation of India (ICICI) was a government institution established on 5 January 1955 and Sir Arcot Ramasamy Mudaliar was elected as the first Chairman of ICICI Ltd. It was structured as a joint-venture of the World Bank, India's public-sector banks and public-sector insurance companies to provide project financing to Indian industry. ICICI Bank was established by ICICI as a wholly owned subsidiary in 1994 in Vadodara. The bank was founded as the Industrial Credit and Investment Corporation of India Bank, before it changed its name to ICICI Bank. In October 2001, the Boards of Directors of ICICI and ICICI Bank approved the merger of ICICI and two of its wholly-owned retail finance subsidiaries, ICICI Personal Financial Services Limited and ICICI Capital Services Limited, with ICICI Bank. The merger of parent ICICI Ltd. into its subsidiary ICICI Bank led to privatization.

In the 1990s, ICICI transformed its business from a development financial institution offering only project finance to a diversified financial services group, offering a wide variety of products and services, both directly and through a number of subsidiaries and affiliates like ICICI Bank. ICICI Bank launched Internet Banking operations in 1998.

ICICI's shareholding in ICICI Bank was reduced to 46% through a public offering of shares in India in 1998, followed by an equity offering in the form of American depositary receipts on the NYSE in 2000. ICICI Bank acquired the Bank of Madura Limited in an all-stock deal in 2001 and sold additional stakes to institutional investors during 2001–02. In 1999, ICICI become the first Indian company and the first bank or a financial institution from non-Japan Asia to be listed on the NYSE.

ICICI, ICICI Bank, and ICICI subsidiaries ICICI Personal Financial Services Limited and ICICI Capital Services Limited merged in a reverse merger in 2002. During the 2008 financial crisis, customers rushed to ICICI ATMs and branches in some locations due to rumours of bank failure. The Reserve Bank of India issued a clarification on the financial strength of ICICI Bank to dispel the rumours.

In 2015, ICICI unveiled an outward remittance platform called Money2World for online outward remittance transactions for non-ICICI and ICICI customers. In March 2020, the board of ICICI Bank Ltd. approved an investment of ₹10 billion (US$120 million) in Yes Bank, resulting in a 5% ownership interest in Yes.

ICICI Bank has contributed to the setting up of a number of Indian institutions to establish financial infrastructure in the country over the years: