BSL may refer to:

Business

• Black Star Line, a former shipping line owned by Marcus Garvey
• BlueScope Steel Limited, an Australian-based flat product steel producer
• Boyne Smelters Limited, an Australian-based aluminium smelter company
• Brookdale Senior Living, a U.S. company that operates senior residences

Education

• Bachelor of Science in Law, an academic degree
• British School of Lomé, Togo, a school in Togo, West Africa

Linguistics

• British Sign Language
• Bhutanese Sign Language

Publications

• Bulletin de la Société de Linguistique de Paris, an academic journal published by the Société de Linguistique de Paris
• Bulletin of Symbolic Logic, from the Association for Symbolic Logic
• Transport Phenomena (book), an engineering textbook also known by its authors' initials (Bird, Stewart, and Lightfoot)

Science and computing

• Biosafety level or biohazard safety level, a set of biocontainment precautions
• Blood sugar level
• Boost Software License, a license popular for C++ projects
• Bootstrap loader, the software involved in booting a computer

Sports

• Basketball Super League (Turkish: Basketbol Süper Ligi), Turkey's premier men's basketball league
• Israeli Basketball Super League, a former name of the Israeli Basketball Premier League

Transportation

• EuroAirport Basel Mulhouse Freiburg (IATA airport code)
• Broad Street Line, a subway line in Philadelphia, Pennsylvania, US

Other uses

• Bangladesh Student League, a students' political organisation in Bangladesh
• Biologic Space Laboratories, the location of the Metroid Fusion video game
• Beam stage loader, a machine that forms part of a longwall mine
• Breed-specific legislation, a type of law to prohibit or restrict the keeping of particular breeds or types of dog