EGS is a three-letter abbreviation of:
Computer:
- Enhanced Graphics System, Graphics system used with the Amiga computer
Engineering and transport:
- Egilsstadir Airport in Iceland (IATA Airport Code)
- Experimental Geodetic Satellite, a Japanese satellite
Education:
- Enfield Grammar School, an English school
- Ermysted's Grammar School, an English school
- European Graduate School, a Swiss private university
Science:
- Electron Gamma Shower, a computer simulation program
- Electronic-grade silicon
- Enhanced Geothermal System, technology to extract electrical energy from geothermic sources
- Entire Genome Sequencing, a term that refers to the sequencing of an organism's entire genome
- European Geophysical Society, resolved, now part of the European Geosciences Union
- Extended Groth Strip, an image taken by the Hubble Space Telescope
Other:
- Emmet G. Sullivan, acronym widely used for the US District Court Judge