| OFFROAD 1566411 · TMA896020 · design | PAL Co. Ltd. | 5 Pharmaceuticals16 Paper18 Leather+1 | Registered | 2015 |
| OFFROAD 1542769 · TMA872905 | Boston Scientific Scimed, Inc. | 10 Medical | Registered | 2014 |
| OPARD 2211901 · TMA1243030 | Shenzhen City LeTu Technology Co., Ltd. | 21 Housewares | Registered | 2024 |
| OPORTUN 2176718 · TMA1227121 · design | Oportun, Inc. | 36 Finance | Registered | 2024 |
| OPORTUN 2176717 · TMA1227120 | Oportun, Inc. | 36 Finance | Registered | 2024 |
| 1791 OPPORTUNE 2103329 · TMA1239430 · design | an individual | 33 Wine | Registered | 2024 |
| OPPORTUNE 1791 2099902 · TMA1239427 | an individual | 33 Wine | Registered | 2024 |
| Overtake 2083787 · TMA1189284 | Owner not shown | 14 Jewellery16 Paper25 Clothing+3 | Registered | 2023 |
| OVERTAKE 320 2057702 · TMA1147010 | SA Designer Parfums Limited | 3 Cosmetics | Registered | 2022 |
| OVEREDGER 2046783 · TMA1191476 · design | an individual | 18 Leather | Registered | 2023 |
| OPHARDT 2045329 · TMA1224912 | OP-Hygiene IP GmbH | 3 Cosmetics5 Pharmaceuticals6 Metal+7 | Registered | 2024 |
| OperationCwrl 2005421 · TMA1131075 | an individual | 24 Textiles | Registered | 2022 |
| OVERTIMEPACK 1992303 · TMA1254545 | INDUSTRIES RAD INC. | 9 Electronics12 Vehicles | Registered | 2024 |
| OVERTURE 1978541 · TMA1094730 | Overture 3D Technologies, LLC | 17 Rubber | Registered | 2021 |
| OVERDOSE 1937451 · TMA1159717 | an individual | 4 Oils9 Electronics34 Tobacco | Registered | 2023 |
| OVERDRIVE 1913185 · TMA1104090 · design | Rajeev Perti GLOBAL CONSUMER PRODUCTS INC | 11 Lighting31 Fresh | Registered | 2021 |
| OVERHIT 1901432 · TMA1083654 · design | NEXON Games Co. Ltd. | 41 Education | Registered | 2020 |
| OVERHIT 1901431 · TMA1092889 · design | NEXON Games Co. Ltd. | 9 Electronics | Registered | 2021 |
| OVERWATCH 1895512 · TMA1085726 | Tulsar Canada Ltd. | 7 Machines9 Electronics | Registered | 2020 |
| OPERATOR 1887846 · TMA1048793 | Parsons Xtreme Golf, LLC | 28 Toys | Registered | 2019 |
| oppHERtunity 1886353 · TMA1087843 | an individual | 35 Advertising36 Finance | Registered | 2020 |
| OpeRATOR 1862393 · TMA1038585 | an individual | 1 Chemicals5 Pharmaceuticals | Registered | 2019 |
| OPERATOR 1853161 · TMA1017485 | INTERCOM, INC. | 35 Advertising42 Science | Registered | 2019 |
| OPERATION 36 1852603 · TMA1014523 | GOLF GENIUS SOFTWARE, INC. | 9 Electronics41 Education | Registered | 2019 |
| OPRADICA 1838890 · TMA1033898 | Mitsubishi Tanabe Pharma Corporation | 5 Pharmaceuticals | Registered | 2019 |