| Single Source Systems, Inc. | Indiana |
| Single Throw Marketing | New Jersey |
| SinglebaseCloud, Inc. | |
| Singlebrook Technology, Inc. | New York |
| SingleFeed | California |
| Singlemind Consulting | |
| SingleOps | Georgia |
| SinglePlatform | New York |
| SinglePoint, Inc. | |
| Singlesource IT | |
| SingleStore, Inc. | California |
| SingleThread | Michigan |
| Singlewire Software, LLC | Wisconsin |
| Singota Solutions | Indiana |
| Singular Ads | |
| Singular Genomics Systems, Inc. | California |
| Singular Innovation | |
| Singular Labs, Inc. | California |
| Singular Security | California |
| Singular Solutions | California |
| Singularity 6 Corporation | |
| Singularity Energy, Inc. | Massachusetts |
| Singularity University | California |
| Singularity University | |
| SingularityHUB | California |
| Singulera Therapeutics, Inc. | |
| SiNON Nano Sciences | |
| Sinopia Biosciences | California |
| Sinte Gleska University | South Dakota |
| Sintel Satellite Services, Inc. | New York |
| Sintesys, LLC | Connecticut |
| SINTX Technologies, Inc. | |
| Sinu | New York |
| SinuSonic | South Carolina |
| SIO Digital | |
| Siolta Therapeutics | |
| SION Browser | Arizona |
| Sion Power Corporation | |
| Sionic Mobile Corporation | |
| Sionna Therapeutics | |
| SIOS Technology Corporation | California |
| Sioux Falls Computer Guy | South Dakota |
| Sioux Falls PC Pro | South Dakota |
| Siouxland Linux Users Group | South Dakota |
| SIP Trunking | Georgia |
| SIP3 | |
| SiPhox, Inc. | |
| Sippel Technologies, Inc. | Missouri |
| Siqsess, LLC | |
| Sira International, LLC | |