| Acronym | Definition |
|---|
| LTI | Linear Time Invariant |
| LTI | Long Term Incentive (NZ) |
| LTI | Lost Time Injury |
| LTI | Lingua Tertii Imperii (language of the NAZI empire, Latin) |
| LTI | Lost Time Incident |
| LTI | Language Technologies Institute (Carnegie Mellon University; Pittsburgh, PA) |
| LTI | London Taxis International (company) |
| LTI | Lincoln Technical Institute (automotive education) |
| LTI | Life Technologies, Inc. |
| LTI | Learning Tools Interoperability (IMS Global Learning Consortium, Inc.) |
| LTI | Lucent Technologies, Inc. |
| LTI | Limited Technical Inspection |
| LTI | Learning Technology Institute |
| LTI | Lowell Technological Institute (Massachusetts) |
| LTI | Licentiate of the Textile Institute |
| LTI | Listowel Technology Inc |
| LTI | Laboratoire de Toxicologie Industrielle (French: Laboratory for Industrial Toxicology; Belgium) |
| LTI | LORAN-C Timing Interface (Sprint) |
| LTI | Language Technology Incorporated |
| LTI | Lower Tactical Internet (battlefield communications network for echelons at brigade and below) |
| LTI | Learning Tree Information |
| LTI | Longtime Integration |
| LTI | Licence de Transport Internationale (France) |
| LTI | Louisiana Technical Institute |
| LTI | Lower Thermosphere and Ionosphere |
| LTI | Leadership Training Institute |
| LTI | Live Training Instrumentation |
| LTI | Lighting Technologies, Inc. (various locations) |
| LTI | Laser Thermal Imaging (Kodak) |
| LTI | Loan to Income (ratio) |
| LTI | Left Thumb Impression (personal identification) |
| LTI | Long-Term Illness |
| LTI | LeTourneau Technologies, Inc. |
| LTI | Ladder Towers International (fire engine ladder tower manufacturer) |
| LTI | Land Title Institute (American Land Title Association) |
| LTI | Learning Tree International |