| Company | Location |
|---|---|
| Oklahoma Nanotechnology Initiative | Oklahoma City, Oklahoma, United States |
| Olma Messen St. Gallen | St. Gallen, Switzerland |
| Olympus America Inc. | Melville, New York, United States |
| Olympus Industrial America | Orangeburg, New York, United States |
| Olympus Partnership Development Group (PDG) | San Jose, California, United States |
| Omedtech LLC | Edmond, Oklahoma, United States |
| Omicron NanoTechnology GmbH | Taunusstein, Germany |
| Omni International: The Homogenizer Company | Marietta, Georgia, United States |
| Omni Tech International Ltd. | Midland, Michigan, United States |
| Omnica Corp. | Irvine, California, United States |
