GEOS

GEOS may refer to:

Computer software

GEOS (8-bit operating system), an operating system originally designed for the Commodore 64
GEOS (16-bit operating system), a DOS-based graphical user interface and x86 operating system
GEOS (securities processing software), an integrated online system for the management and processing of securities
GEOS (software library), geometry engine open source

GEOS (eikaiwa), an English conversation teaching company based in Japan
GEOS circle, an intersection of four lines that are associated with a generalized triangle
GEOS (satellite), a research satellite from ESRO (1978–1982)
GEOS-1, 2 (Geodetic Earth Orbiting Satellite), research satellites from NASA
GEOS-3 (Geodynamics Experimental Ocean Satellite), a research satellite from NASA
GEOS-1 (Goddard Earth Observing System version 1), Earth model from NASA EOS Program