| Acronym | Definition |
|---|
| OII | Office of Insurance Information |
| OII | Oxford Internet Institute (UK) |
| OII | Office of Innovation and Improvement |
| OII | Organization Intersex International |
| OII | Open Information Interchange |
| OII | Online Internet Institute |
| OII | Out Island Interiors (interior decorating) |
| OII | Orthopaedic International, Inc. (Philippines) |
| OII | Online Innovation Institute |
| OII | Operations-Intelligence Interface |
| OII | Office of Industrial Innovation (US NSF) |
| OII | Organización Internacional Intersexuales (Spanish: International Organization of Intersexuals) |
| OII | Occupational Injury or Illness |