MBL
- Free Bolivia Movement
- Free Brazil Movement
- Macquarie Bank Limited
- Malaysian Basketball League
- Manistee County-Blacker Airport
- Mannan-binding lectin
- Many-body localization
- Marie Byrd Land
- Marine Biological Laboratory
- Midwest Basketball League
- Monoclonal B-cell lymphocytosis
- Montclair-Boonton Line
- Montebello Bus Lines
- National Security College (Israel)