SEM or Sem can refer to:
Computing
Search engine marketing, promoting websites by increasing their visibility in search engine results Security event manager, a security log tool used on data networks
Economics and management Stock Exchange of Mauritius, the principal stock exchange of the island country of Mauritius Strategic enrollment management, an element of planning for new growth at a university or college Samsung Electro-Mechanics, a South Korean company
Energy Single Electricity Market, the integration of the electricity sectors of the Republic of Ireland and Northern Ireland in a single market Strategic energy management, continuous improvement process for energy efficiency based on behavioral change
Mathematics and statistics Structural equation modeling, in data analysis Simultaneous equations model, in econometrics Standard error of the mean in statistics
Places Craig Field (Alabama) (IATA code: SEM), a public airport four miles southeast of Selma, in Dallas County, Alabama Sem, Ariège, a former commune in the Ariège department in southwestern France Sem, Norway, a village in Tønsberg Municipality in Vestfold county, Norway Sem Municipality, a former municipality in Vestfold county, Norway
Science and technology Scanning electron microscope Space Experiment Module, of the Freestar experiment on space shuttle Columbia Sistema Eléctrico de Magallanes, an electrical power grid of Chile SEM, instrument (seismometer) of the Surface Science Platform (Kazachok) mission ExoMars 2022 A protecting group in organic chemistry, see 2-(trimethylsilyl)ethoxymethyl chloride (SEM-Cl)
Schools, organisations, societies
Society for Experimental Mechanics, an engineering professional organization. The School of Ecclesiastic Music the school of Byzantine Music in Mount Lebanon Swedish Evangelical Mission Society for Ethnomusicology, an ethnomusicology in Indiana, US Science and Engineering Magnet, a school in Dallas, Texas, US S.E.M. Group civil engineering company based in South Australia Steam Engine Makers' Society, early British trade union Shandong Engineering Machinery, owned by Caterpillar Inc. State Secretariat for Migration (Switzerland)
People Shem or Sem, one of the sons of Noah, as depicted in the Bible Sem (given name), a usually masculine first name Sem (artist) (1863–1934), French caricaturist Elise Sem (1870–1950), Norwegian barrister, women's activist, and sports official Ingebjørg Dahl Sem (born 1938), Norwegian Christian writer Ingebjørg Sem (1931–2009), Norwegian actress John Sem (born 1973), Papua New Guinean Olympic boxer Niels Arntzen Sem (1782–1859), Norwegian politician Suy Sem (born 1947), Cambodian politician
Other Super Étendard Modernisé, a French fighter aircraft Self-evaluation maintenance theory, a psychological theory of self Synthesizer Expansion Module, an Oberheim synthesizer New Austrian tunnelling method or Sequential Excavation Method Sports and exercise medicine