IOC most commonly refers to the International Olympic Committee.

IOC or IoC may also refer to:

• IBM Open Class, IBM C++ product
• Indicator of compromise, an artifact likely indicating a computer intrusion
• Inversion of control, a software design pattern

• Indian Ocean Commission
• Indian Oil Corporation, large Indian oil and gas company
• Indian Orthodox Church, Kerala, India
• International Olive Council
• Initiative on Cities, urban research institute at Boston University
• Initiatives of Change, international organisation "building trust across the world's divides" (formerly Moral Re-Armament)
• Intergovernmental Oceanographic Commission of Unesco
• International Ornithological Committee, former name of the International Ornithologists' Union
• International Order of Characters, an organization dedicated to improving the fields of aviation and aerospace
• Iron Ore Company of Canada

• Icon of Coil, Norwegian electronic music band
• Immediate or cancel, a type of order used on some stock exchanges
• Index of coincidence, the technique in cryptography of counting the number of times that identical letters appear
• Initial operating capability, minimum level of deployment, especially in the US military
• Intraoral camera, a device used to take photos of the inside of a patient's mouth
• Italian organized crime