LEM

LEM may refer to:


 * LEM, a musical instrument with the brand name Generalmusic
 * Lake Erie Monsters (now the Cleveland Monsters), a professional ice hockey team based in Ohio
 * Lamina emergent mechanism, found in pop-up books
 * Law of excluded middle, in classical logic
 * Lay Eucharistic Minister, in the Catholic, Episcopal or Lutheran Churches
 * Learnable Evolution Model, an evolutionary computation method
 * LEM domain-containing protein 3, a membrane protein associated with laminopathies
 * Leyton Midland Road railway station in the United Kingdom, station code LEM
 * Liquid Elastomer Molding, a gasket technology developed by the Federal-Mogul Corporation
 * Luís Eduardo Magalhães, a city in the state of Bahia, Brazil
 * Lunar Excursion Module, the original designation of the Apollo Lunar Module
 * Lymphocyte expansion molecule