MBL may refer to:
Education Marine Biological Laboratory, an international center for research and education in biology, biomedicine, and ecology Master of Business and Law, a two-year master's degree credential National Security College (Israel)
Politics Free Bolivia Movement (Spanish: Movimiento Bolivia Libre), a political party in Bolivia Free Brazil Movement (Portuguese: Movimento Brasil Livre), a liberal-conservative political movement in Brazil
Science Mannan-binding lectin (or mannose-binding lectin), a protein capable of binding certain sugars and polysaccharides Many-body localization, a state of matter in which a local set of particles cannot reach thermal equilibrium Monoclonal B-cell lymphocytosis, a condition that resembles chronic lymphocytic leukemia (CLL)
Sport Malaysian Basketball League, former name of the Malaysia National Basketball League, the pre-eminent men's basketball league in Malaysia Midwest Basketball League, a semi-professional men's basketball league which operates in the Midwestern United States
Transportation Manistee County-Blacker Airport (IATA/FAA code MBL), an airport in the US state of Michigan Montclair-Boonton Line, a commuter rail line in North Jersey in the US state of New Jersey Montebello Bus Lines, a local transit agency serving the San Gabriel Valley in Southern California
Other uses Marie Byrd Land, region of West Antarctica Macquarie Bank Limited, name of the Macquarie Group (a publicly traded Australian financial-services corporation) prior to its restructuring in 2007 Berlin missal (MBl), 15th century Glagolitic manuscript