| Abbreviation | Definition |
|---|---|
| SDTC | Sustainable Development Technology Canada |
| SEA | Science and Engineering Alliance |
| SEACAP | South East Asia Community Access Programme |
| SEACOPS | South East Alaska Coalition Opposed to Pirating of our Salmon |
| SEAI | Science and Education Alliance, Inc. |
| SEAL | Society For Experimental Arts And Learning |
| SEARCH | Society for Education Action and Research in Community Health |
| SEC | Save The Earth Campaign |
| SEC/AAS | Southeast Conference of the Association for Asian Studies |
| SECA | Southern Early Childhood Association |
| SECC | State Employees Combined Campaign |
| SECFM | SouthEast Community Farmers' Market |
| SEDC | Southern Economic Development Council |
| SEE | Surgical Eye Expeditions |
| SEEC | Southeast Environmental Education Committee |
| SEED | Social and Environmental Enterprise Development |
| SEED | SouthEast Effective Development |
| SEEDCO | Structured Employment Economic Development Corporation |
| SEEI | Surgical Eye Expeditions International |
| SE-EPPC | Southeast Exotic Pest Plant Council |