| OPTIRESOURCE 1315152 · TMA744245 | an individual | 9 Electronics16 Paper42 Science | Registered | 2009 |
| OPTRIENT 2229030 · TMA1252871 | Koch Agronomic Services, LLC | 1 Chemicals | Registered | 2024 |
| OPPODREAM 2217314 · TMA1246692 | an individual | 24 Textiles | Registered | 2024 |
| OPTIRINSE 2184544 · TMA1230591 | Kobayashi Pharmaceutical Co. Ltd. | 5 Pharmaceuticals10 Medical | Registered | 2024 |
| OPTERA 2149792 · TMA1191032 | Point380, Inc. | 35 Advertising42 Science | Registered | 2023 |
| OBTURO 2114669 · TMA1216150 | Owner not shown | 1 Chemicals | Registered | 2023 |
| OPTERION 2075846 · TMA1168456 | an individual | 5 Pharmaceuticals10 Medical42 Science | Registered | 2023 |
| OPTRELL 2051449 · TMA1228572 | Biosense Webster, Inc. | 10 Medical | Registered | 2024 |
| OPTRAFFIC 2048599 · TMA1146982 | OPTRAFFIC CO. LTD. | 9 Electronics | Registered | 2022 |
| OpteraPro 2010253 · TMA1110004 | Nufarm Australia Limited | 5 Pharmaceuticals | Registered | 2021 |
| OPETRIA 2009926 · TMA1260714 | Wakamoto Pharmaceutical Co. Ltd. | 5 Pharmaceuticals | Registered | 2024 |
| OpteraSeed 2007733 · TMA1109972 | Nufarm Australia Limited | 5 Pharmaceuticals | Registered | 2021 |
| OPTOWIRE 1975535 · TMA1223444 · design | OPSENS INC. | 10 Medical | Registered | 2024 |
| OPTORO 1961857 · TMA1255657 | Optoro, Inc. | 35 Advertising | Registered | 2024 |
| OPTRAGLOSS 1944338 · TMA1102670 | IVOCLAR VIVADENT, INC. | 5 Pharmaceuticals10 Medical | Registered | 2021 |
| OPHYTRIUM 1931651 · TMA1155623 | an individual | 1 Chemicals | Registered | 2022 |
| OPTRAFINE 1890514 · TMA1101406 | IVOCLAR VIVADENT, INC. | 10 Medical | Registered | 2021 |
| OVODERM 1850406 · TMA1089597 · design | an individual | 1 Chemicals5 Pharmaceuticals | Registered | 2020 |
| OPTIRUN 1841136 · TMA1057462 | an individual | 9 Electronics41 Education42 Science | Registered | 2019 |
| Optiarc 1816152 · TMA999051 | VINPOWER, INC. | 9 Electronics | Registered | 2018 |
| OPTREX 1790747 · TMA1045313 | OPTREX LIMITED | 3 Cosmetics5 Pharmaceuticals10 Medical | Registered | 2019 |
| OPTIWRAP 1779670 · TMA1016983 | KUHN NORTH AMERICA, INC. | 7 Machines | Registered | 2019 |
| OPTIREADER 1767461 · TMA1013394 | Petroleum Analyzer Company, LP | 9 Electronics | Registered | 2019 |
| OPTREX 1766217 · TMA979830 · design | OPTREX LIMITED | 3 Cosmetics5 Pharmaceuticals | Registered | 2017 |
| OPTRUST 1733115 · TMA941697 · design | an individual | 9 Electronics16 Paper35 Advertising+1 | Registered | 2016 |