BL (or similar) may refer to:

• Boys' love, a Japanese term for fiction featuring romantic relationships between male characters
• BL Publishing, a division of the wargames manufacturing company, Games Workshop
• Boston Legal, a US legal comedy-drama

• Balmer Lawrie, an Indian central public sector undertaking conglomerate
• Bell Labs, an audio-technology research and design enterprise
• Boys' Latin School of Maryland, a US private school
• Brisbane Lions, an Australian rules football team in the Australian Football League
• British Library, the UK's national library
• British Leyland, a former UK vehicle manufacturing company
• Pacific Airlines (IATA code BL), a low-cost airline
• Lytvyn Bloc, a Ukrainian political party

• Bitter lemon, a carbonated soft drink
• Bud Light, an American lager beer

• Bachelor of Laws (B.L.), an undergraduate degree in law
• Barrister-at-Law, a degree and professional qualification in Ireland, Northern Ireland and Nigeria.

• BL postcode area, UK, covering Bolton and Bury in Greater Manchester
• Bakerloo line, a London Underground line
• Banja Luka, a city in Bosnia and Herzegovina
• Saint Barthélemy [ISO country code BL], a Caribbean overseas collectivity of France
• Basel-Landschaft (Basel-Country), a canton of Switzerland
• Province of Belluno, Italy (car-license plate abbreviation BL)
• Bolivia (FIPS Pub 10-4 and obsolete NATO digram BL), a central South American country
• Brazil, LOC MARC code

• BL (logic), the logic of continuous t-norms
• BL register, the low byte of an X86 16-bit BX register
• Bootloader

• Accupressure or acupuncture points, e.g., BL-34 or BL-54
• Burkitt's lymphoma, a disease
• Borderline lepromatous leprosy, a disease

• B − L (B minus L), in physics
• Backhoe loader, an engineering vehicle
• Black light, a lamp which operates near the ultraviolet range of light
• Carl Ludwig Blume, botanist, abbreviated Bl.
• Breech-loading weapon, designated BL in British artillery
• One of the Thiele/Small electromechanical parameters of loudspeakers
• Base Line, a theoretical reference line from which features are measured or compared

• Bundesliga, the highest association football league in Germany

• Ы, Yery or Yeru, a letter in the Cyrillic script, which resembles lowercase B and L written together (bl)
• BL, braille shorthand for blind
• Bakerloo line, a London Underground line
• Bill of lading, a receipt issued by a shipping carrier
• Blessed, an honorific prefix given to beatified Catholics
• Blue Line (Washington Metro)
• Body language, a form of non-verbal communication
• Bhutia-Lepcha, an ethnic grouping of people for which there are reserved seats in the Sikkim Legislative Assembly, in India

• List of BL dramas