LGM
LGM may refer to:
Lady International Correspondence Chess Grand Master
Last Glacial Maximum
LGM (film) or Let's Get Married, an Indian Tamil-language romantic drama film
Libre Graphics Meeting
Little green men, a stereotypical portrayal of extraterrestrials
Little Green Men Games

See also 
LGM-1, a pulsar
LGM-2, a star with anomalous variations in brightness
LGM-25 Titan I ICBM
LGM-25C Titan II ICBM
LGM-30 Minuteman ICBM
LGM-118 Peacekeeper ICBM
Little Green Men (disambiguation)