EFX

EFX may refer to:
 * EFX (show), a Las Vegas show
 * EFX (album), an album of the show
 * Enterprise Framework (EFx), see EFx Factory
 * Enerflex Systems, a Canadian company listed as EFX on the Toronto Stock Exchange
 * Equifax, a U.S. consumer credit reporting agency listed as EFX on the New York Stock Exchange
 * Effects Extension (EFX), a set of digital signal processing extensions for the OpenAL audio API
 * .efx, the Everett Efax file format, see List of file formats
 * EFX item allocation - a rule for fair allocation of indivisible objects among people with different preferences.