| Acronym | Definition |
|---|
| NOI | Net Operating Income |
| NOI | Notice of Intent |
| NOI | Nation of Islam |
| NOI | Notice of Inquiry |
| NOI | Notice of Interest |
| NOI | Neuro Orthopaedic Institute |
| NOI | New Organizing Institute |
| NOI | Notice of Inspection (checked baggage) |
| NOI | No Offense Intended |
| NOI | No Other Information |
| NOI | National Oilwell, Inc. (est. 1841; various locations) |
| NOI | Nature of Illness |
| NOI | National Orchestral Institute (College Park, MD) |
| NOI | Notice of Infringement (copyright/trademark) |
| NOI | National Olympiad in Informatics |
| NOI | Non-Operational Intelligence (US Navy) |
| NOI | Not Otherwise Indicated |
| NOI | National Optics Institute |
| NOI | Notizie Omosessuali Italiane (Italian) |
| NOI | Not Otherwise Identified |
| NOI | Notice of Injury |
| NOI | Notes Object Interface (Lotus Notes development) |
| NOI | Northern Optotronics Inc. (Canada) |
| NOI | Number of Installments |
| NOI | Node Operator Interface |
| NOI | Notice of Involvement |
| NOI | Nitrogen & Other Inerts |
| NOI | Netherlands Oost-Indië |