| Semiconductor Network | Seoul |
| SEMICS, Inc. | Gyeonggi |
| Semsgames | Jeonbuk |
| Semyung University | |
| Sensor System Technology Co., Ltd | Gyeonggi |
| SentBe, Inc. | |
| Seoil University | |
| Seojeong University | |
| Seokyeong University | |
| Seorin Bioscience Co., Ltd | Gyeonggi |
| Seoul Analytica | Seoul |
| Seoul Business Agency | |
| Seoul Christian University | |
| Seoul Culture Arts University | |
| Seoul Cyber University | |
| Seoul Digital University | |
| Seoul Jangsin University | |
| Seoul National University | Seoul |
| Seoul National University - Department of Mathematical Sciences | |
| Seoul National University - School of Computer Science & Engineering | Seoul |
| Seoul National University of Education | |
| Seoul National University of Science&Technology | |
| Seoul Polytech Education Co., Ltd | Seoul |
| Seoul Precision Optics, Inc. | Gyeonggi |
| Seoul Robotics | Seoul |
| Seoul Semiconductor Co., Ltd | Gyeonggi |
| Seoul Social Welfare Graduate University | |
| Seoul Techno Holdings, Inc. | Seoul |
| Seoul Technopark | Seoul |
| Seoul Ventures | Seoul |
| Seoul VR Technologies | Seoul |
| Seoul Web Design, Inc. | Seoul |
| Seoul Women's College of Nursing | |
| Seoul Women's University | |
| Seoulz | Seoul |
| Seowon University | |
| SEOWOOSNC Co., Ltd | Seoul |
| Seoyeong University | |
| SepoaSoft | Seoul |
| Seroun Electronics Co., Ltd | Incheon |
| Sewoo Incorporation | Gyeonggi |
| SFA Semicon Co., Ltd | South Chungcheong |
| SGA Co., Ltd | Seoul |
| Shaperon | Seoul |
| Sherpa Ventures | |
| Shin Ansan University | |
| Shin Gyeongju University | |
| Shin Poong Pharm Co., Ltd | Seoul |
| Shingu College | |
| Shinhan University | |