Egis or EGIS has a variety of meanings, including:

• An alternate spelling for aegis.
• An acronym for Erieye Ground Interface Segment, military software package which is part of the Erieye radar and is sometimes confused with the Aegis combat system.
• Egis Rt. (Egis Ltd), a Hungarian pharmaceutical company, based in Kőbánya, Hungary.
• Egis explosives detector, a gas chromatography-mass spectrometry-based explosives detector, manufactured by Thermo Detection (formerly Thermedics)