MLO might refer to:
- Malibu Locals Only, a group of youths local to Malibu, California, US
- Medio-lateral Oblique, a standard view used in mammography
- Milos Island National Airport, Greece, IATA code
- Misanthropic Luciferian Order, a Satanic organisation
- Mortgage Loan Originator Housing and Economic Recovery Act of 2008 term for "loan officer"
- Mount Laguna Observatory, near San Diego, California, US
- Mycoplasma-like organism, earliest name for phytoplasmas