| Acronym | Definition |
|---|
| IGI | International Genealogical Index |
| IGI | Indira Gandhi International (airport; India) |
| IGI | I'm Going In |
| IGI | International Gemological Institute |
| IGI | Idea Group Inc. (Canada) |
| IGI | Instrument Ground Instructor (certification; US FAA) |
| IGI | Indian Institute of Geomorphologists (University of Allahabad; Uttar Pradesh, India) |
| IGI | Image-Guided Intervention (medical procedure) |
| IGI | I Get It |
| IGI | Infotech Global, Inc (Piscataway, NJ) |
| IGI | Institute of Geologists of Ireland |
| IGI | International Gaming Institute (University of Nevada, Las Vegas, NV) |
| IGI | Institute for Graphic Interfaces (South Korea) |
| IGI | Infectious Gastrointestinal Illness |
| IGI | Iowa Governor's Institute (University of Iowa) |
| IGI | Institution Gang Investigator (prisons) |
| IGI | Inspector General for Investigations |
| IGI | Investigation Group International, Inc. (Washington, DC) |
| IGI | Initial Gap Increasing Method |
| IGI | Inner Grid Injection |