IIAC may refer to:
Sports Interstate Intercollegiate Athletic Conference, a now-defunct college athletics conference, formerly Illinois Intercollegiate Athletic Conference Iowa Intercollegiate Athletic Conference, the former name of a college athletics conference now known as the American Rivers Conference
Other uses Incheon International Airport Corporation, a corporation which operates Incheon International Airport (Airport of Republic of Korea)
Institut Interdisciplinaire d'Anthropologie du Contemporain, a French research institute, which became the laboratoire d'anthropologie politique (LAP) in 2022.