ELF (plural ELFs)
- (computing) Initialism of Executable and Linking Format (a common object file format for Unix)
- (electronics) Initialism of Extremely low frequency (band of radio frequencies from 3 to 30 hertz)
- (linguistics) Initialism of English as a Lingua Franca.
- Initialism of Earth Liberation Front (a radical environmentalism group)
- Initialism of Elvish Linguistic Fellowship (an organization that studies the invented languages of J. R. R. Tolkien)
- Initialism of Endangered Language Fund (a non-profit organization)