Abu Dhabi Investment Authority is a sovereign wealth fund established to diversify the wealth of Abu Dhabi, which is predominantly generated from oil revenues, by investing outside of the UAE.

ADIA's total assets are estimated at USD 600 billion to 875 billion as of 2007, making it the world's largest sovereign wealth fund. The size of those assets constitute about five times the size of UAE's 2007 GDP. Some of ADIA's notable investments include EFG-Hermes HoldingEFG-Hermes Holding (9%) another 4.9% stake in US Citigroup and 10% stake in Qatar TelecomQatar Telecom.

ADIA started out in 1976 by replacing the Financial Investments Board as the arm designated to invest in local and regional equities, bonds, and real estate. ADIA eventually expanded its activities by launching a private equity department in 1989. It also opened an Emerging markets department in 2005.

The Abu Dhabi government reshuffled its investments in 2007 by establishing Abu Dhabi Investment Council (ADICADIC) to take over and focus on investments within the UAE. ADIA shifted its focus outside the UAE and transferred its local investments over to ADICADIC, which included Abu Dhabi Commercial BankAbu Dhabi Commercial Bank, National Bank of Abu DhabiNational Bank of Abu Dhabi, Abu Dhabi Investment CompanyAbu Dhabi Investment Company and Etihad AirwaysEtihad Airways.