IAB

IAB may refer to:

Organisations

Institute of Architects Bangladesh, a professional organisation for architects in Bangladesh
Interactive Advertising Bureau, for the online advertising industry
Internal Affairs Bureau, part of the New York City Police Department, US
International Agrarian Bureau or Green International, based in Prague, Czech Republic
Institute of Accountants and Bookkeepers, UK
International Association of Bryologists, promoting bryology (the study of mosses, liverworts, and hornworts)
Internet Advertising Bureau, a UK trade association
Internet Architecture Board, a committee of the Internet Engineering Task Force (IETF)
Islami Andolan Bangladesh, political party in Bangladesh
Israel Association of Baseball, to promote and develop baseball in Israel