| OSTUNE 2033345 · TMA1213921 | OSRAM GmbH | 9 Electronics11 Lighting | Registered | 2023 |
| OSTENIL 2209946 · TMA1280861 | TRB CHEMEDICA SA | 5 Pharmaceuticals | Registered | 2025 |
| OSTENIL 0883068 · TMA544719 | TRB CHEMEDICA SA | 5 Pharmaceuticals | Registered | 2001 |
| OSTENE 2210774 · TMA1271204 | BAXTER INTERNATIONAL INC. | 5 Pharmaceuticals | Registered | 2024 |
| OSTENT 1799976 · TMA993949 · design | Shenzhen Ostent Technology Co. Ltd. | 28 Toys | Registered | 2018 |
| Ostand 2326521 | Shenzhen Torras Technology Co.Ltd. | 9 Electronics | Pending | 2024 |
| Ostana 2255367 | Ostana Inc. | 9 Electronics35 Advertising42 Science | Pending | 2023 |
| OZYTINI 2087136 · TMA1170114 | BOEHRINGER INGELHEIM INTERNATIONAL GMBH | 5 Pharmaceuticals | Registered | 2023 |
| OKSTENCK 2233346 · TMA1256640 | Ningbo Huahongzhengte Information Technology Co. Ltd | 18 Leather | Registered | 2024 |
| OCTANE 2177613 · TMA1259456 | OTOY, Inc. | 9 Electronics42 Science | Registered | 2024 |
| OCTANE 2110124 · TMA1180549 · design | Octane Systems Canada Corp. | 9 Electronics42 Science | Registered | 2023 |
| OCTANE 1948224 · TMA1182255 | Octane Systems Canada Corp. | 9 Electronics35 Advertising42 Science | Registered | 2023 |
| OCTANE 1852618 · TMA1081010 | an individual | 7 Machines9 Electronics16 Paper | Registered | 2020 |
| OCTANE 1735617 · TMA979180 | Vicimus Inc. | 9 Electronics42 Science | Registered | 2017 |
| OCTANE 1594796 · TMA855769 | Polaris Industries Inc. | 12 Vehicles | Registered | 2013 |
| OCTANE 1518489 · TMA839786 | Choice Spine, LLC | 10 Medical | Registered | 2013 |
| OCTANE 1514689 · TMA997579 | Edmonton Oilers Hockey Corp. | 9 Electronics14 Jewellery16 Paper+8 | Registered | 2018 |
| OSTEON 1500300 · TMA844408 | Platinum Performance Inc. | 5 Pharmaceuticals | Registered | 2013 |
| OCTANE 1486252 · TMA798900 · design | Sirius XM Radio LLC | 41 Education | Registered | 2011 |
| OCTANE 1416726 · TMA763427 | Octane Medical Group Inc. | 42 Science | Registered | 2010 |
| OCTANE 1341894 · TMA720521 | 9296-0186 Québec inc. | 33 Wine | Registered | 2008 |
| OCTANE 1286078 · TMA716096 | JAYCO, INC. a corporation of Indiana | 12 Vehicles | Registered | 2008 |
| OKTANT 0857478 · TMA535245 | an individual | 3 Cosmetics14 Jewellery20 Furniture+2 | Registered | 2000 |
| OCTAN 0735638 · TMA446468 · design | Owner not shown | 28 Toys | Registered | 1995 |
| OCTANE 2339574 | Owner not listed | 12 Vehicles | Pending | 2024 |