| ONUREG 1767275 · TMA966383 | Celgene Corporation | 5 Pharmaceuticals | Registered | 2017 |
| ONUREG 2048468 · design | Celgene Corporation | 5 Pharmaceuticals | Pending | 2020 |
| ONERJI 2116595 · TMA1148250 | Mitsubishi Tanabe Pharma Corporation | 5 Pharmaceuticals | Registered | 2022 |
| ONRES 2360245 | OnRes Systems Inc. | 42 Science | Pending | 2024 |
| OneReach 1510875 · TMA834981 | Berk-Tek LLC | 9 Electronics | Registered | 2012 |
| OnRègle 1746882 · TMA1005681 | BidSettle Inc. | 45 Legal | Registered | 2018 |
| ONEIRIC 1662378 · TMA933365 | Blueline Equipment Inc. | 25 Clothing | Registered | 2016 |
| OMNIREZ 0823755 · TMA486554 | ISP Investments LLC | 1 Chemicals | Registered | 1997 |
| OneArch 2341602 | OSSTEM IMPLANT CO., LTD | 10 Medical | Pending | 2024 |
| ONARKEN 2225058 | LapSafe Holdings Limited | 9 Electronics37 Construction41 Education+1 | Pending | 2022 |
| ONERECALL 2161610 | Inmar RX Solutions, Inc. | 42 Science45 Legal | Pending | 2022 |
| OMROWZY 2240079 · TMA1256995 | GLAXO GROUP LIMITED | 5 Pharmaceuticals | Registered | 2024 |
| Oumers 2185761 · TMA1232451 | Shenzhen Fansiyi Technology Co. Ltd. | 8 Hand | Registered | 2024 |
| OMNIRACK 2158767 · TMA1178304 | Prym Consumer USA Inc. | 20 Furniture | Registered | 2023 |
| ONEWORKSPACE 365 2102821 · TMA1175001 | NIRIX Inc. | 9 Electronics42 Science | Registered | 2023 |
| OWNERSBOX 2044532 · TMA1280070 | Ownersbox 3.0 Corporation | 9 Electronics25 Clothing38 Telecommunications+1 | Registered | 2025 |
| OMORC 1991107 · TMA1108149 | SHENZHEN QIAO DAKE E-COMMERCE LTD. | 9 Electronics18 Leather | Registered | 2021 |
| OMERACT 1939885 · TMA1141671 | OMERACT | 9 Electronics16 Paper35 Advertising+2 | Registered | 2022 |
| Omorc 1924303 · TMA1103525 | SHENZHEN QIAO DAKE E-COMMERCE LTD. | 7 Machines8 Hand12 Vehicles+4 | Registered | 2021 |
| OMRISNI 1923746 · TMA1112350 | an individual | 5 Pharmaceuticals | Registered | 2021 |
| OMERUS 1893323 · TMA1133717 | an individual | 6 Metal7 Machines9 Electronics+3 | Registered | 2022 |
| OMERS 1838206 · TMA1008219 · design | OMERS Administration Corporation | 9 Electronics16 Paper35 Advertising+1 | Registered | 2018 |
| ONRACK 1742002 · TMA1025731 | Dell Inc. | 9 Electronics | Registered | 2019 |
| ONRESPID 1727361 · TMA1031846 | SANOFI | 5 Pharmaceuticals | Registered | 2019 |
| OMARS 1709188 · TMA937273 · design | Wellmade Corporation Limited | 9 Electronics28 Toys | Registered | 2016 |