| Sebastian Thüer | Buenos Aires |
| Secure Informatica, S.R.L. | Santa Fe |
| Seek Sistemas | Buenos Aires |
| SEI Servicios Especiales en Informática S.A. | Buenos Aires |
| Selfmy Web Design | Buenos Aires |
| SEO Argentina | Buenos Aires |
| Seo Express | Buenos Aires |
| SEOnet | Buenos Aires |
| Seotronix | |
| Serfe | Santa Fe |
| Sergio Montagna | Buenos Aires |
| Service Hard | Buenos Aires |
| Servicio Satelital, S.A. | |
| Servicios Internet | Buenos Aires |
| Servicios y Sistemas de Computación | Buenos Aires |
| SES Sistemas Electrónicos S.A. | Buenos Aires |
| Seta Sistemas | Buenos Aires |
| SextaGeneración | Buenos Aires |
| SHIFTA | |
| Shopear | |
| SIADNet | Buenos Aires |
| SIASA | Buenos Aires |
| Siblings Software | |
| Sidesys IT Solutions | Buenos Aires |
| Sierra Technology Group, S.A. | Buenos Aires |
| Siglo Informática | Buenos Aires |
| Signos | Buenos Aires |
| SimplesPasos.com | Buenos Aires |
| SimplificarWeb | Buenos Aires |
| SimulAr | Buenos Aires |
| Simza Computacion | Buenos Aires |
| Sinaptia | |
| Siscard S.A. | Córdoba |
| Siscard, S.A.. | Buenos Aires |
| Sisgra | Santa Fe |
| Sisted | Buenos Aires |
| Sistek | Buenos Aires |
| Sistema de Informes Laborales | Buenos Aires |
| Sistema Isis | Buenos Aires |
| Sistemas Aplica | Buenos Aires |
| Sistemas Criticos | Buenos Aires |
| Sitios Hispanos | Santa Fe |
| siwol.com.ar | Buenos Aires |
| Skater Elephant | |
| Skyonline | Buenos Aires |
| Skytel | Buenos Aires |
| Smallcode | Buenos Aires |
| SmartFran | |
| smartGSM | Buenos Aires |
| SmartSol | Buenos Aires |