Several meanings of the initialism BSA are:

• Bank Secrecy Act
• Basic Skills Agency
• Birmingham Small Arms Company (motorcycles etc.)
• Blackwell Science Asia
• Body surface area
• Boston Society of Architects
• Botanical Society of America
• Bovine serum albumin
• Boy Scouts of America
• British School at Athens
• British Snowboarding Association
• British Social Attitudes
• British Society of Audiology
• British Sociological Association
• British Stammering Association
• British Surfing Association
• Broadcasting Standards Authority
• Building Societies Association
• Bulgarian Studies Association
• Business Software Alliance
• UK Boarding Schools Association