BSI may refer to: Businesses and organizations BSI Ltd, formerly Banca della Svizzera Italiana BSI Group or British Standards Institution The Baker Street Irregulars, a literary society devoted to Sherlock Holmes Bank Saderat Iran Bank Syariah Indonesia Bible Society of India Botanical Survey of India British Society for Immunology Federal Office for Information Security (German: Bundesamt für Sicherheit in der Informationstechnik) Bureau of Special Investigation, Myanmar Other uses BSI coupling, a railway coupling or coupler Back-illuminated sensor, also known as backside illumination (BSI) sensor, a type of digital image sensor Bloodstream infections Body substance isolation Balesin Airport, IATA code BSI See also BS (disambiguation) BS1 (disambiguation) CBSI (disambiguation) WBSI (disambiguation) KBSI (disambiguation)