| Abbreviation | Definition |
|---|---|
| SECU | State Employment Credit Union |
| SEIU | Service Employees International Union |
| SEKU | Shotokan England Karate Union |
| SEKU | Shotokan of England Karate Union |
| SESAC | Society Of European Stage Authors And Composers |
| SEU | Service Employees Union |
| SFCU | Shell Federal Credit Union |
| SFCU | Sikorsky Financial Credit Union |
| SFCU | Siouxland Federal Credit Union |
| SFCU | Somerset Federal Credit Union |
| SFCU | Spokane Firefighters Credit Union |
| SFCU | Stanford Federal Credit Union |
| SFCU | Strategic Federal Credit Union |
| SFTU | San Francisco Tenants Union |
| SFTU | Singapore Federation of Trade Unions |
| SFTU | Swaziland Federation of Trade Unions |
| SFTU | Swiss Federation of Trade Unions |
| SFWU | Service & Food Workers Union |
| SFWU | Service and Food Workers Union |
| SFWU | Seychelles Federation of Workers Union |