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 Bangunan Sultan Iskandar, border checkpoint in Johor, Malaysia Hot R&B/Hip-Hop Songs, a Billboard chart with the shortcut "BSI"

See also BS (disambiguation) BS1 (disambiguation) CBSI (disambiguation) WBSI (disambiguation) KBSI (disambiguation)