| Sahmyook Health University | |
| Sahmyook University | |
| Saltcake | |
| Saltlux | Seoul |
| Samjin Pharm | Seoul |
| Samjung Tech Co., Ltd | |
| Samoh Pharm Co., Ltd | |
| Samsung | Seoul |
| Samsung Advanced Institute of Technology | |
| Samsung Bioepis | Incheon |
| Samsung Biologics | Incheon |
| Samsung Developers | Seoul |
| Samsung E&A | |
| Samsung Electro-Mechanics | |
| Samsung Medison Co., Ltd | Seoul |
| Samsung SDI Co., Ltd | Seoul |
| Samsung SDS | |
| Samsung Venture Investment Corporation | Seoul |
| Samsung Ventures Investment Corporation | Seoul |
| Samwon Act Co., Ltd | |
| Sandoll | Seoul |
| Sangji University | |
| Sangmyung University | |
| SAPEON Korea, Inc. | |
| SapiensBio | |
| Sarangnet | Seoul |
| Satrec Initiative | Daejeon |
| Sawnics | Seoul |
| SBI Cosmoney Co., Ltd | Seoul |
| SBtron | Seoul |
| SCADAICT | Seoul |
| Scatter Lab Co., Ltd | Seoul |
| Schmidt | Seoul |
| SCK Corporation | Seoul |
| SCM Lifescience | |
| SDPlex | Gyeonggi |
| Seasun Biomaterials, Inc. | Daejeon |
| SeaVantage, Inc. | Seoul |
| Second Space Co., Ltd | Seoul |
| Secure Guard Technology, Inc. | Seoul |
| Security Platform Co., Ltd | Gyeonggi |
| Secuve | Seoul |
| Sejin Chun | |
| Sejong Cyber University | |
| Sejong University | |
| SEJUFA Co., Ltd | |
| Selko Electronics | Seoul |
| Seloco, Inc. | Seoul |
| Selvas AI | Seoul |
| SEMES | South Chungcheong |