Geography, the study of the Earth and its features

Geometry, the study of spatial relationships

Geology, the study of the Earth's structure

General Education Officer, the basic rank of teachers of the Ministry of Education in Singapore

Geocentric, a model of the universe that places the earth at its centre

Geodesy, also known as geodetics, the study of the measurement and representation of the earth

Geocaching, an outdoor activity that involves using navigational techniques to finds geocaches

Grupo Especial de Operaciones, a division of the Spanish police

Geostationary orbit, a circular orbit directly above the earth's equator

Geo, the composer for the J-pop group Sweetbox

Geopolitics, the analysis of history, geography and social science with respect to international politics

Geosynchronous orbit, an orbit that has the same period as the Earth's sidereal rotation

Geo (artist), the Korean manhwa artist.

Geo (automobile), a defunct brand of entry-level cars produced by General Motors

Geo. is sometimes an abbreviation of the name George.

Geo-exchange, a heating and cooling system

Geo (microformat), a microformat for marking up WSG84 geographical coordinates in (X)HTML

Geothermal (geology), heat sources from within the Earth

Global Environment Outlook, an environmental assessment produced by the United Nations

GEO 600, a detector for gravitational radiation

GEO, the IATA code for Cheddi Jagan International Airport

Geo (marketing), a discipline within marketing analysis

Geolocation, the science of determining the real-world location of a website or website visitor

GEO (magazine), a popular scientific magazine

Estadio Casas GEO, stadium in Mexicali, Mexico

Geo TV, a leading television channel in Pakistan

Geo Bogza, a Romanian poet and essayist.

Geo Stelar is the main protagonist in Mega Man Star Force.

Geo or gio, is a creek (inlet) or gulley in the Orkney and Shetland Islands

Geocoding or GeoTagging, encoding coordinates in to features, images, web ages and other data records