| Acronym | Definition |
|---|
| GCI | Ground Circuit Interrupter |
| GCI | Getty Conservation Institute |
| GCI | Green Cross International (non-profit international environmental organization) |
| GCI | Global Commerce Initiative |
| GCI | Growth Competitiveness Index |
| GCI | Great Cities Institute |
| GCI | Global Commons Institute (UK) |
| GCI | ground control intercept (US DoD) |
| GCI | Great Coasters International (Sunbury, PA) |
| GCI | Global Consultants Inc |
| GCI | Gwich'in Council International (Alaska and Canada) |
| GCI | Graduate Careers Ireland |
| GCI | Gray Card Index |
| GCI | Gymnastiska Centralinstitutet (Sweden) |
| GCI | Global Change Institute |
| GCI | Generalized Conversational Implicature |
| GCI | Grace Churches International |
| GCI | Grace Communion International (formerly Worldwide Church of God) |
| GCI | Georgia Correctional Industries |
| GCI | Global Communication Infrastructure |
| GCI | Guernsey, Channel Islands, United Kingdom - Guernsey (Airport Code) |
| GCI | General Conditions of Insurance (various organizations) |
| GCI | Great Cranberry Island (Maine, USA) |
| GCI | Galt Collegiate Institute (Cambridge, Ontario) |
| GCI | Grey Communications International |
| GCI | General Communication Incorporated |
| GCI | Guild of Calamitous Intent (fiction, Venture Bros.) |
| GCI | Genetics Citation Index |
| GCI | Guides to Canadian Industry |
| GCI | Gross Cash Invested |
| GCI | Glenlawn Collegiate Institute |
| GCI | Geocentric Celestial Inertial Coordinate System |
| GCI | Generic Channel Interface |
| GCI | General Consumer Interest |
| GCI | Generic Communications Index |
| GCI | Global Change Initiative |
| GCI | Gaussian Co-Channel Interferer |
| GCI | Gateway Customer Interface |
| GCI | Grade Crossing Inventory |
| GCI | Global Capital Investors LP |
| GCI | Guerra Consulting Inc (Overland Park, KS) |
| GCI | Green Campus initiative (various schools) |
| GCI | Green Communities Initiative (various locations) |
| GCI | Gminne Centrum Informacji (Polish: Local Information Center) |
| GCI | General Compenents, Inc. (various locations) |
| GCI | Guitar Center, Inc. (Delaware) |
| GCI | Golf Course Irrigation |