IAC may refer to:

• IAC (chemotherapy), a chemotherapy regimen
• Internal auditory canal

• IAC (company), an American media company
• International Academy of Ceramics
• International Academy of Cytology, a scientific global NGO for cytopathologists and cytologists
• India Against Corruption
• Indigenous Advisory Council, an Australian government agency
• Industrial Assessment Center, an American training program and research program
• Instituto de Astrofísica de Canarias, an astrophysical research institute in the Canary Islands
• InterAcademy Council, global network of academies of science, engineering, and medicine
• Inter-African Committee on Traditional Practices Affecting the Health of Women and Children, a rights organization
• International Action Center, a leftist organization
• International Advisory Council, operates the International Teletraffic Congress
• International Aerobatic Club, an American sports governing body
• International Astronautical Congress
• Interstate Athletic Conference, an all-boys high school sports league in the Washington, D.C. area
• Interstate Aviation Committee, a civil aviation authority in the Commonwealth of Independent States
• Irish Air Corps, the aviation wing of the Irish Defense Forces
• Israeli-American Council, an American nonprofit umbrella organization
• Istituto per le Applicazioni del Calcolo Mauro Picone, an Italian applied mathematics research institute

• Indoor Africa Cup, the Indoor hockey at Africa
• Indy Autonomous Challenge, a 2021 race for autonomous cars at the Indianapolis Motor Speedway

• I'm a Celebrity...Get Me Out of Here! (British TV series), in TV Shows
• Idle air controller, in an internal combustion engine
• Image of the absolute conic, in computer vision; see Camera resectioning
• Imperfect authentic cadence, in music
• Indigenous Aircraft Carrier, an Indian Navy designation for aircraft carriers built in India
• Idol Star Athletics Championships, a popular South Korean TV variety program (alternately abbreviated as "ISAC")
• Ineffective assistance of counsel, in US law
• Infrastructure as Code, a technique for managing computer hardware, as software.
• Interactive activation and competition networks, a kind of neural network
• Interapplication communication, in computing
• International access code, in telecommunications

• IACS (disambiguation)