IIF

IIF may refer to:

• IIf (abbreviation for immediate if) and ?:, the inline-if computing function
• Indirect immunofluorescence, one of several types of immunofluorescence
• Institute of International Finance, an association of international financial institutions
• International Indonesia Forum, an organisation which holds annual interdisciplinary seminars in Indonesia.
• International Institute of Forecasters, a nonprofit organization devoted to advancing the science of forecasting
• Intuit Interchange Format, a file format used by Intuit's Quickbooks software