| OPENDO 1540461 · TMA885738 | an individual | 9 Electronics16 Paper35 Advertising+4 | Registered | 2014 |
| Openatey 2216098 · TMA1245393 | Guangzhou Kexing Trading Co., Ltd. | 25 Clothing | Registered | 2024 |
| OPENMEET 2193848 · TMA1271172 · design | SHOKZ (SINGAPORE) PTE. LTD. | 9 Electronics | Registered | 2024 |
| OPIANT 2173498 · TMA1198227 | Opiant Pharmaceuticals, Inc. | 5 Pharmaceuticals | Registered | 2023 |
| OPIANT 2173497 · TMA1198226 · design | Opiant Pharmaceuticals, Inc. | 5 Pharmaceuticals | Registered | 2023 |
| OPENDOTS 2151098 · TMA1192925 · design | SHOKZ (SINGAPORE) PTE. LTD. | 9 Electronics | Registered | 2023 |
| OPENAUDIO 2054027 · TMA1152968 | BOSE CORPORATION | 9 Electronics | Registered | 2022 |
| OVENTURE 2014662 · TMA1260866 | The Big O, LLC | 14 Jewellery18 Leather35 Advertising | Registered | 2024 |
| OPENTIME 2004856 · TMA1264875 | an individual | 42 Science | Registered | 2024 |
| OVINTIV 2001221 · TMA1281899 | Ovintiv Trademarks Inc. | 4 Oils35 Advertising37 Construction+3 | Registered | 2025 |
| OPENTEMP 1999111 · TMA1258825 · design | Opentemp Recruiting Inc. | 9 Electronics35 Advertising | Registered | 2024 |
| OVENTE 1981564 · TMA1116537 | Topnet, Inc. | 7 Machines11 Lighting20 Furniture+1 | Registered | 2021 |
| OPENTAP 1958105 · TMA1220061 · design | Keysight Technologies, Inc. | 9 Electronics42 Science | Registered | 2024 |
| OVENTUS 1956541 · TMA1165175 | OPEN AIRWAY DENTAL SOLUTIONS LTD. | 10 Medical40 Treatment | Registered | 2023 |
| OPENTAP 1943549 · TMA1220060 | Keysight Technologies, Inc. | 9 Electronics42 Science | Registered | 2024 |
| O2VENT 1936445 · TMA1191344 | OPEN AIRWAY DENTAL SOLUTIONS LTD. | 10 Medical | Registered | 2023 |
| OVHenterprise 1927020 · TMA1098930 | OVH | 9 Electronics35 Advertising36 Finance+5 | Registered | 2021 |
| OPENDOCK 1915419 · TMA1093603 | OpenDock, LLC | 42 Science | Registered | 2021 |
| OPENTEX 1911525 · TMA1121962 · design | an individual | 10 Medical | Registered | 2022 |
| OPENTUBE 1901257 · TMA1128775 | Amazon Technologies, Inc. | 9 Electronics35 Advertising38 Telecommunications+3 | Registered | 2022 |
| OpenTour 1883343 · TMA1063979 | GITI TIRE PTE. LTD. a private limited company organized under the laws of Singapore | 12 Vehicles | Registered | 2019 |
| oventrop 1824977 · TMA1065213 | OVENTROP GmbH & Co. KG | 6 Metal7 Machines9 Electronics+5 | Registered | 2019 |
| OVOMET 1811926 · TMA1027711 | an individual | 1 Chemicals5 Pharmaceuticals | Registered | 2019 |
| OPENTEC 1766045 · TMA1030049 | Owner not shown | 6 Metal | Registered | 2019 |
| OPENID 1727604 · TMA1059867 | Open ID Foundation | 35 Advertising41 Education42 Science | Registered | 2019 |