EI or Ei may refer to: Arts and media "E.I." (song), a single by Nelly E/I, a type of children's television programming shown in the United States Ei (album), an album by Maija Vilkkumaa "Ei" (song), its first single Eerie, Indiana, an American television series Enrique Iglesias, Spanish pop music singer-songwriter Exposure index, the film speed rating of photographic film as exposed Businesses and organizations Aer Lingus (IATA code EI), the flag airline of Ireland The Earth Institute, a collection of research centers at Columbia University Education International, a global union federation of teachers' trade unions Elektronska Industrija Niš, electronics enterprise based in Niš, Serbia Energy Institute, the main professional organization for the energy industry within the UK Engineers Ireland, the professional body for engineers and engineering in Ireland Enterprise Ireland, is the Irish government organisation responsible for the development and growth of Irish enterprises in world markets. Expeditors International, the global logistics and freight forwarding company based out of Seattle, Washington The Electronic Intifada, an online publication covering the Israeli-Palestinian conflict from a Palestinian perspective Linguistics ⟨ei⟩, a digraph found in some Latin alphabets The original name of the Greek letter Epsilon ɛɪ in the International Phonetic Alphabet (IPA) Places Ei, Kagoshima, a town located in Ibusuki District, Kagoshima, Japan Emerald Isle, North Carolina, a town in Carteret County, North Carolina, United States Science, technology, and mathematics Ei (prefix symbol), the prefix abbreviation of the binary unit prefix "exbi" Earth Interactions, a scientific journal published by the American Meteorological Society, American Geophysical Union, and Association of American Geographers Ei Compendex, an engineering bibliographic database Electron ionization, an ionization method in which energetic electrons interact with gas phase atoms or molecules to produce ions Electronic ignition, a variety of modern ignition system Engineering Index, an article index for engineering journals Engineer intern, an intermediary step to becoming a Professional Engineer Environmental illness (multiple chemical sensitivity), a chronic medical condition characterized by symptoms that the affected person attributes to exposure to low levels of chemicals Ionization energy (EI), the energy required to remove one electron from one atom to another Equine influenza, the disease caused by strains of Influenza A that are enzootic in horse species Exponential integral, a special function defined on the complex plane given the symbol Ei Other uses Education Index, a United Nations measure of the level of educational development in a country Emotional intelligence, the ability