| Ohio-Israel Ag & CleanTech Initiative | |
| Ohio.net | Ohio |
| Ohlone College | California |
| Ohm Systems, Inc. | Pennsylvania |
| OhmConnect, Inc. | California |
| Ohmcraft | New York |
| Ohmite Mfg. Co. | Illinois |
| Ohmium International, Inc. | |
| OHO | |
| OHP Marketing Services | Iowa |
| Ohso! Design | |
| OIC, L.P. | |
| Oidview | Massachusetts |
| OIKOS Software | |
| OIKOS Software, Inc. | New Hampshire |
| Oilware, Inc. | Texas |
| Oisin Biotechnologies | Washington |
| Ojas Innovative Technologies, Inc. | California |
| Okami Medical | California |
| okcDEV | Oklahoma |
| Okeen | |
| Okera, Inc. | California |
| Oklahoma Baptist University | Oklahoma |
| Oklahoma Christian University | Oklahoma |
| Oklahoma City University | Oklahoma |
| Oklahoma College Assistance Program | |
| Oklahoma Life Science Fund | |
| Oklahoma Medical Research Foundation | |
| Oklahoma Panhandle State University | Oklahoma |
| Oklahoma Space Industry Development Authority | |
| Oklahoma State University Department of Computer Science | Oklahoma |
| Oklahoma State University Department of Mathematics | Oklahoma |
| Oklahoma State University Institute of Technology | Oklahoma |
| Oklahoma State University-Oklahoma City | Oklahoma |
| Oklahoma State University-Tulsa | Oklahoma |
| Oklahoma Web Design & Hosting | Oklahoma |
| Oklahoma Web Media | Oklahoma |
| Oklahoma Wesleyan University | Oklahoma |
| Oklo, Inc. | |
| Okogen, Inc. | California |
| Okonomi, Inc. | |
| Okta, Inc. | California |
| Oktara | California |
| Oktay Technology | New Jersey |
| Okteto, Inc. | California |
| Ola Moana Marketing | |
| Olaf Solutions, Inc. | Louisiana |
| Olapic, Inc. | New York |
| Olaris, Inc. | Massachusetts |
| Olark | Michigan |