| Acronym | Definition |
|---|
| LSI | Large-Scale Integration |
| LSI | LSI Logic Corporation (stock symbol) |
| LSI | Latent Semantic Indexing (datamining) |
| LSI | Language Studies International |
| LSI | Learning Systems Institute (Florida State University) |
| LSI | Lead Systems Integrator |
| LSI | Linear Shift-Invariant |
| LSI | Love, Sex, Intelligence (song by Shaman) |
| LSI | Life Styles Inventory (Human Synergistics) |
| LSI | Langelier Saturation Index |
| LSI | Laboratory Safety Institute |
| LSI | Laser Spine Institute (Tampa, FL) |
| LSI | Lutheran Services in Iowa |
| LSI | Lëvizja Socialiste Për Integrim (Albanian party: Socialist Movement for Integration) |
| LSI | Lunar Science Institute |
| LSI | Logistic Services International, Inc |
| LSI | Lake Superior and Ishpeming Railroad |
| LSI | Large Scale Industries |
| LSI | Shetland Islands /Shetland Isd, Scotland, United Kingdom - Shetland Islands (Airport Code) |
| LSI | Latent Semantic Information |
| LSI | Infantry Landing Ship |
| LSI | Lean Sustainment Initiative |
| LSI | Liquid Silicon Infiltration (materials science engineering technique) |
| LSI | Language Skills Institute (Philippines) |
| LSI | Listing Site Inspection |
| LSI | Lake Shore Industries |
| LSI | Laser Solutions Inc. |
| LSI | Large Scale Incident (information security, disaster response) |
| LSI | List of Serials Indexed for Online Users |
| LSI | Line Status Indication |
| LSI | Lead Service Integrator |
| LSI | Largest Single Item |
| LSI | Lear Siegler, Incorporated |
| LSI | Land Sea Interface |
| LSI | Legal Support Inspection |
| LSI | Leadership Strengths Interview (USACE) |
| LSI | Laserex Systems, Inc. |
| LSI | Local Service Itemization |
| LSI | Lifesave International (biological research and education) |
| LSI | Landed Surface Interrogator |
| LSI | Land-Shelf Interactions Initiative |
| LSI | Low Ship Impact |
| LSI | Lighting, Starting, Ignition (automotive/batteries) |
| LSI | Launch Success Indicator |
| LSI | Legacy Systems International (Toronto, ON, Canada) |