EF or ef may refer to:

Arts and entertainment

  • Ef (band), a post-rock band from Sweden
  • Ef: A Fairy Tale of the Two., a Japanese adult visual novel series by Minori, or its anime adaptations

Businesses and organizations

  • Eagle Forum, an anti-feminist conservative interest group
  • Earth First!, movement, in environmentalism
  • Eastern Fare, a music institution and production house in Bangalore, India
  • EF Education First, an international education organization
  • The Elias Fund, a non-profit organization
  • Far Eastern Air Transport (IATA code EF)
  • Ethereum Foundation, Swiss non-profit foundation

Linguistics

  • Ef (Cyrillic) (Ф, ф), a letter in the Cyrillic alphabet
  • F (F, f), a letter in the Latin alphabet

Science

Biology and psychology

  • Ejection fraction, in cardiovascular physiology
  • Elongation factors, proteins that are important in protein synthesis
  • Executive functions, a theorized cognitive system in psychology that controls and manages other cognitive processes

Physics

  • Electric field, in physics
  • Exafarad, an SI unit of electric capacitance
  • Fermi energy or Fermi level (E<sub>F</sub>), both concepts in quantum mechanics

Other sciences

  • Ecological footprint, the measure of the demand the population has on the environment
  • Enhanced Fujita scale (EF scale), an improved version of the Fujita scale used to rate the intensity of tornadoes
  • Ice cap climate, which is abbreviated to EF in the Köppen climate classification

Technology

  • Canon EF camera, a manual focus 35mm SLR
  • Canon EF lens mount, Canon's autofocus lens mount
  • Entity Framework, an object-relational mapping (ORM) framework for the .NET Framework

Other uses

  • Extraordinary Form, a phrase used to describe the Catholic liturgy of the 1962 Roman Missal
  • Era Fascista, the Italian fascist calendar
  • Extra fine, a condition of a coin
  • Eurofurence, a furry convention in Berlin, Germany