SION
| Acronym | Definition |
|---|---|
| SION | Standard Input Output Norms (Director General of Foreign Trade; India) |
| SION | Solent Investment Opportunity Network (Portsmouth, UK) |
| SION | Stuurgroep Integraal Overlandvliegen Nederland (Dutch: Steering Group Cross Country Flying Netherlands) |
| SION | Shut in Over Night (oil drilling) |