EI

• "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 • Ei (name), a Japanese and Burmese name • Emotional intelligence, the ability to identify, assess, and control emotions • Employment insurance, the unemployment benefits system of Canada • Encyclopaedia of Islam, an encyclopaedia of the academic discipline of Islamic studies • Enhanced interrogation, a euphemism for torture • Ex infra, a Latin phrase meaning 'from below' • Extreme ironing, an extreme sport and a performance art • Esercito Italiano, Italian language for Italian Army • Raiden Ei, the Electro Archon in 2020 video game Genshin Impact, who appears as the Raiden Shogun • Republic of Ireland (aircraft registration prefix EI)