LMO may refer to:
- Living modified organism
- Lombard language of northern Italy, ISO 639:1 code
- RAF Lossiemouth, Scotland, IATA airport code
- Lithium manganese oxide, a cathode material for lithium-ion batteries
- LMO (album), by Rage and Lingua Mortis Orchestra
- Lanthanum manganite (LaMnO), an inorganic compound
LMO is the debut album by Lingua Mortis Orchestra and the 21st studio album by German heavy metal band Rage released on August 2, 2013 through Nuclear Blast Records. The production was helmed by Charlie Bauerfeind.