| Object Management Group | Massachusetts |
| Object Partners, Inc. | Minnesota |
| Object Radiance, Inc. | California |
| Object Systems International, LLC | Utah |
| ObjectGraph | New York |
| Objective | Utah |
| Objective Arts, LLC | Illinois |
| Objective Interface Systems, Inc. | Virginia |
| Objective Labs, LLC | Minnesota |
| Objective Marketing | |
| Objective Systems, Inc. | Pennsylvania |
| Objective Systems, LLC | North Carolina |
| Objective Technologies, Inc. | New York |
| Objective, Inc. | California |
| Objectivity, Inc. | California |
| ObjectRiver, Inc. | Massachusetts |
| ObjectRocket | |
| ObjectSecurity USA | California |
| ObjectSpectrum, LLC | Texas |
| Objectstream, Inc. | |
| ObjectStyle, LLC | |
| ObjectVideo, Inc. | Virginia |
| ObjectVista, LLC | Minnesota |
| ObjectWave | Illinois |
| Objexx Engineering, Inc. | Massachusetts |
| Oblato, Inc. | New Jersey |
| Oblenio Bio | |
| Obligo | |
| Oblong Industries | |
| Obo, Inc. | California |
| Obra Capital, Inc. | |
| Observable, Inc. | California |
| Observational Health Data Sciences and Informatics | |
| Observe, Inc. | California |
| Observe.ai | California |
| ObserveIT | Massachusetts |
| ObservePoint | Utah |
| Obsidian Security | |
| Obsidian Systems | New York |
| Obsidian Therapeutics, Inc. | |
| Obsidian Vertex | |
| Obu Interactive | California |
| Obvio Health USA, Inc. | New York |
| Obvio, Inc. | |
| Obvious Ventures | California |
| Obviously AI, Inc. | California |
| Obvius Robotics, Inc. | |
| OC Rugged Laptops | California |
| OC Systems | Virginia |
| OCA Ventures | Illinois |