OSEC
| Acronym | Definition |
|---|---|
| OSEC | Office Suisse d'Expansion Commerciale (French: Swiss Office for Commercial Expansion; now Swiss Agency for Foreign Trade Promotion) |
| OSEC | Ocean Systems Engineering Corporation |
| OSEC | On-Site-Electrolytic-Chlorination (Wallace & Tiernan) |
| OSEC | Open Security Evaluation Criteria |
| OSEC | Office of Sustainable Ecosystems and Communities (EPA) |
| OSEC | Observatório de Segurança das Estradas e Cidades (Portugal) |
| OSEC | Office Systems Education & Counseling |
| OSEC | Ovarian Surface Epithelial Cell (biology) |