| Onephrase | |
| OnePlace Capital | Iowa |
| OnePlusOne Solutions | |
| OnePulse | Texas |
| OneQode, LLC | |
| Onera Health | California |
| Onering Networks | Georgia |
| OneScreen.AI | Massachusetts |
| OneSeventeen Media, PBC | |
| OneSignal | California |
| Onesite, Inc. | Oklahoma |
| OneSource | |
| OneSource Technology | Kansas |
| OneSource Technology Group, LLC | Indiana |
| OneSource Virtual | Texas |
| OneSpan | Massachusetts |
| Onespot | Texas |
| Onesto Web Development | |
| OneStream | Michigan |
| OneStudyTeam, Inc. | |
| Onethird | |
| OneThirtyFive | Ohio |
| OneThree Biotech | New York |
| OneTraction | California |
| OneTraction Impact Innovation Ventures | California |
| OneTrust, LLC | Georgia |
| OneTwenty1 Immersive, Inc. | |
| OneUp | Pennsylvania |
| Oneupweb | Michigan |
| OneValley | California |
| OneValley | |
| OneView Commerce | Massachusetts |
| OneVision Solutions | Texas |
| OneWeb | Virginia |
| OneWhoServes, Inc. | North Carolina |
| Onezoneroone | |
| Onfleet, Inc. | California |
| OnFulfillment | California |
| Ongig, Inc. | |
| Ongoing Operations, LLC | Maryland |
| OnGraph Technologies, LLC | New York |
| OnHand | Massachusetts |
| Onikom | |
| Onimod Global | Illinois |
| Onion Corporation | |
| Onit, Inc. | Texas |
| Onity Group, Inc. | |
| Onix | Ohio |
| Onixlab, LLC | |
| Onkos Surgical | New Jersey |