| OTAKON 1426882 · TMA762682 | Otakorp, Inc. | 41 Education | Registered | 2010 |
| OTICON 0266795 · TMA129028 | Owner not shown | 9 Electronics10 Medical | Registered | 1962 |
| OTICON 2217250 | Owner not shown | 9 Electronics10 Medical44 Medical | Pending | 2022 |
| OUTISAN 2182361 · TMA1230291 | Shenzhen Yanwai Technology Co. Ltd. | 7 Machines8 Hand11 Lighting+8 | Registered | 2024 |
| OTOSAN 0851895 · TMA507081 | Owner not shown | 3 Cosmetics5 Pharmaceuticals | Registered | 1999 |
| Odashen 2217819 · TMA1245544 | Shenzhen Yimei Network Technology Co., Ltd. | 7 Machines | Registered | 2024 |
| OATSOME 2163729 · TMA1203167 | BetterBody Foods & Nutrition LLC | 29 Meat30 Coffee35 Advertising+2 | Registered | 2023 |
| OITSME 2156829 · TMA1208796 · design | Shenzhen Abufan Technology Co.Ltd | 34 Tobacco | Registered | 2023 |
| OATSMART 2097940 · TMA1189401 | BetterBody Foods & Nutrition LLC | 29 Meat30 Coffee35 Advertising | Registered | 2023 |
| OATSOME 2048211 · TMA1125156 | BetterBody Foods & Nutrition LLC | 29 Meat30 Coffee | Registered | 2022 |
| Outgang 2013357 · TMA1131118 | Outgang Inc. | 41 Education42 Science | Registered | 2022 |
| OTOKAMA 1930941 · TMA1139227 | SUGIYO USA, INC. | 29 Meat | Registered | 2022 |
| OUTCOMEMD 1848026 · TMA1054906 | OutcomeMD, Inc. | 9 Electronics35 Advertising42 Science | Registered | 2019 |
| OUTCAMER 1840253 · TMA1015857 · design | Sailvan Times Co. Ltd. | 18 Leather22 Ropes28 Toys | Registered | 2019 |
| OUTCOME 1828265 · TMA1077411 | Orbis Communications Inc. | 9 Electronics | Registered | 2020 |
| OUTSMART 1814573 · TMA1012643 · design | an individual | 9 Electronics35 Advertising41 Education+1 | Registered | 2019 |
| OTZUND 1712003 · TMA1039259 | BOEHRINGER INGELHEIM INTERNATIONAL GMBH | 5 Pharmaceuticals | Registered | 2019 |
| OUTSHINE 1697777 · TMA983939 | Adama Agan Ltd. | 5 Pharmaceuticals | Registered | 2017 |
| OUTOKUMPU 1659355 · TMA959652 · design | an individual | 1 Chemicals6 Metal7 Machines+5 | Registered | 2017 |
| OUTSUNNY 1634735 · TMA894663 · design | AOSOM E-COMMERCE INC. | 8 Hand11 Lighting18 Leather+3 | Registered | 2015 |
| Outcamp 1607315 · TMA878038 | Owner not shown | 35 Advertising38 Telecommunications39 Transport+3 | Registered | 2014 |
| OutSmart 1513021 · TMA870459 | Innovention Concepts Inc. | 9 Electronics16 Paper28 Toys | Registered | 2014 |
| OTCHENASH 1510092 · TMA818257 | SKLL PRODUCTION INC. | 33 Wine35 Advertising40 Treatment+1 | Registered | 2012 |
| OTISMED 1490928 · TMA841287 | OtisMed Corporation | 10 Medical40 Treatment | Registered | 2013 |
| ODOSCAN 1410477 · TMA766855 | Envirosuite Limited | 9 Electronics37 Construction42 Science | Registered | 2010 |