SIAC is an acronym used by several bodies:
Securities Industry Automation Corporation, a subsidiary of the NYSE Euronext Singapore International Arbitration Centre, a not-for-profit international arbitration organisation Sistema Integrado de Artilleria de Campaña (English: Integrated Field Artillery System), a modern field howitzer, manufactured in Spain Sociedad Interamericana de Astronomía en la Cultura, an organization in the field of cultural astronomy in the Americas Southern Indiana Athletic Conference, an American high school athletic conference Southern Intercollegiate Athletic Conference, an NCAA Division II collegiate athletic conference, in the Southern United States Special Immigration Appeals Commission, a superior court of record in the United Kingdom
See also
SIA (disambiguation)