ISB is an acronym for each of the following: In music:

Incredible String Band, a British musical group of the late 1960s

International School of Boston, an international school located in Cambridge, Massachusetts, United States of America

Indian School of Business, a business school in Hyderabad, India

Islamabad International Airport (IATA code "ISB"), also known as Chaklala Airbase, an airport located in Rawalpindi, Pakistan

The International Submarine Band, a 1960s country-rock group featuring Gram Parsons

International School Bangkok, an international school located in Nonthaburi, Thailand; the school used to be located in Bangkok

International School of Beijing, an international school located in Beijing, China

Islamic Society of Boston, a muslim community center and mosque based in Boston, Massachusetts, United States of America

International School of Beaverton, an international school located in Aloha, Oregon, USA

International School Basel, an international school located in Basel, Switzerland.

International School of Brussels, an international school located in Brussels, Belgium

Islamic Society of Britain, a national voluntary organisation

Institute for Systems Biology, a non-profit research institute dedicated to the study and application of systems biology

independent sideband, a radio modulation mode used in some AM radio transmissions

International School of Bergen, an international school located in Bergen, Norway

International Society of Bassists, an international society dedicated to the double bass

The International Staff Band of the Salvation Army