OPIA
| Acronym | Definition |
|---|---|
| OPIA | Office of Public Interest Advising (Harvard University) |
| OPIA | Ontario Printing and Imaging Association |
| OPIA | Oklahoma Private Investigators Association (est. 1984) |
| OPIA | Ontario Plumbing Inspectors Association, Inc. (Canada) |
| OPIA | Optical Precision Instrument Associates |