| SILA Büro- und Computersysteme | |
| SILA International Marketing GmbH | |
| Silbersaiten Bangiev und Bangiev GbR | Lower Saxony |
| Silent Systems GmbH | North Rhine-Westphalia |
| Silgra | Bavaria |
| Silicon Allee | Berlin |
| Silicon Line GmbH | Bavaria |
| Silicon Materials | Bavaria |
| Silicon Planet GmbH | Hamburg |
| Silicon Radar GmbH | |
| Silicon Saxony e.V. | Saxony |
| Silicon Software GmbH | Baden-Württemberg |
| Silicon Solutions & Consulting GmbH | |
| Silicon.de | |
| Silmor | Saxony |
| Siltronic AG | |
| SILVER ATENA Electronic Systems Engineering GmbH | Bavaria |
| silver.solutions GmbH | |
| Silvergames.com | |
| Silversurfer7 GmbH | North Rhine-Westphalia |
| SIM Automation GmbH | |
| SIM Security & Electronic System GmbH | Rhineland-Palatinate |
| Simax Electronics GmbH | North Rhine-Westphalia |
| Simba Computer Systeme GmbH | Baden-Württemberg |
| Simcon Kunststofftechnische Software GmbH | North Rhine-Westphalia |
| SimilarSiteSearch | |
| Simmeth System GmbH | Bavaria |
| Simon ARC GmbH | Baden-Württemberg |
| Simple Web-Solutions GmbH | Hesse |
| SimpleSYN | Lower Saxony |
| simpleTechs GmbH | |
| SimpleThings | Hesse |
| Simplify C++ | Hamburg |
| Simplify Techologies GmbH | Hesse |
| Simsalamedia | Bavaria |
| SimScale | Bavaria |
| SIMsoft | Baden-Württemberg |
| Simssee Klinik GmbH | |
| Simuloptics GmbH | Bavaria |
| Singhammer dtSoftware GmbH | Bavaria |
| Singleron Biotechnologies | |
| singularIT GmbH | Saxony |
| Singulus Technologies AG | |
| Sinkacom AG | Hesse |
| Sinner Datenservice GmbH | Brandenburg |
| Sinnoptics Bastian Bodemeyer, Myriam Eismann, Arndt Lau GbR | Baden-Württemberg |
| Sinnovo IT Services GmbH | Saxony-Anhalt |
| SINOVO Health Solutions GmbH | |
| SINTEC Informatik GmbH | Bavaria |
| Sinus Electronic Vertriebs GmbH | Baden-Württemberg |