| OpsDog, Inc. | |
| Opsera, Inc. | |
| Opsin Biotherapeutics, Inc. | |
| OpsRamp, Inc. | California |
| Opstream | New York |
| OpSuite | Maryland |
| Opswat Academy | |
| OPSWAT, Inc. | California |
| Opt It, Inc. | Illinois |
| Optable | |
| OptDyn, LLC | Delaware |
| OpTech | Michigan |
| Optelos | Texas |
| Optera | Colorado |
| Opterra Energy Services, LLC | |
| Opterus R&D, Inc. | |
| Optery | California |
| OptFirst, Inc. | Florida |
| OPTi Technologies, Inc. | California |
| Opti-Mate, Inc. | Pennsylvania |
| OPTI-UPS International Corporation | California |
| Opti9 | Nebraska |
| Optic Fusion | Washington |
| Optica | |
| Optica Technologies, Inc. | Colorado |
| Optical Cable Corporation | Virginia |
| Optical Communications Group | New York |
| Optical Wavelength Laboratories, Inc. | Wisconsin |
| Optical Zonu Corporation | California |
| Opticaltel | Florida |
| Opticlose, Inc. | |
| Opticon, Inc. | Washington |
| Opticonx | Connecticut |
| Optics & Photonics News | District of Columbia |
| Optics Technology, Inc. | New York |
| OpticWise, Inc. | |
| Opticyte, Inc. | Washington |
| Optidge | |
| Optieum Biotechnologies, Inc. | |
| OptiFuse | California |
| Optigo Networks, Inc. | |
| Optii | Texas |
| OptiJob, Inc. | New Jersey |
| Optilogic | Michigan |
| Optima Computer Services | Louisiana |
| Optima Design Studio | California |
| Optima Technology Associates, Inc. | Pennsylvania |
| Optimal | District of Columbia |
| Optimal Access | California |
| Optimal AI | |