| Sonoma Wire Works | California |
| SonoMotion | California |
| Sonora Software | Arizona |
| SonoraDesignWorks | Arizona |
| Sonoran Biosciences, Inc. | |
| Sonoran PPC | |
| Sonorous | California |
| Sonos, Inc. | |
| SonoThera, Inc. | California |
| SonoVascular, Inc. | |
| Sonraí Security | New York |
| Sons of Thunder Software | Wisconsin |
| Sontec Instruments, Inc. | |
| Sontiq | Massachusetts |
| Sony Biotechnology, Inc. | |
| Sony Creative Software, Inc. | Wisconsin |
| Soofy, LLC | |
| Sookbox | |
| Soona | |
| Sooner Marketing | |
| SOOS | Vermont |
| Soostone, Inc. | New York |
| Soothsayer Analytics | Michigan |
| Soovu Labs, Inc. | |
| Sophelle | Massachusetts |
| SOPHIA Learning, LLC | Minnesota |
| Sophia Solutions | Georgia |
| Sophilabs, Inc. | New York |
| Sophilabs, Inc. | |
| Sophist Solutions, Inc. | Massachusetts |
| Sophisticated Logic | Florida |
| SophSoft, Inc. | Michigan |
| SopReg Consulting | Massachusetts |
| SopReg Consulting, LLC | |
| Sopris Capital, LLC | New York |
| Sora Finance | |
| Soraban | |
| Sorc'd | |
| Sorcero, Inc. | |
| Sorenson Capital | Utah |
| Sorenson Communications | Utah |
| Sorenson Communications, LLC | |
| Soreto | Massachusetts |
| SoRo Systems, Inc. | Vermont |
| Soroco | Massachusetts |
| Sorrento Therapeutics, Inc. | |
| Sorriso Pharmaceuticals | |
| Sorriso Technologies | Massachusetts |
| Sortfolio, Inc. | |
| Sortira | |