GSI

GSI may refer to:

Science and technology

 * Geological Strength Index
 * Gonadosomatic Index
 * UK Government Secure Intranet
 * Grid Security Infrastructure, a computer networking specification
 * "Global Systems Integrator", large managed technology services providers

Businesses

 * Gemological Science International, gemstone identification/grading/appraisal services
 * Geophysical Service Incorporated, an American petroleum exploration corporation
 * Guangzhou Shipyard International, a Chinese state-owned shipbuilder
 * GSI Commerce, now eBay Enterprise, an American e-commerce company

Scientific organizations

 * GSI Helmholtz Centre for Heavy Ion Research, Germany
 * Geographical Society of Ireland
 * Geospatial Information Authority of Japan
 * Geological Survey of India
 * Geological Survey of Ireland

Other organizations

 * Global Security Initiative
 * Gabinete de Segurança Institucional da presidência da república (Institutional Security Cabinet), Brazil
 * Gustav Stresemann Institute, a German educational charity

Other uses

 * Graduate student instructor, a teaching fellow at some US universities
 * Grand-Santi Airport, French Guiana (IATA code GSI)