| ORGREEN 2008773 · TMA1205680 | Owner not shown | 9 Electronics | Registered | 2023 |
| ORAGARD 1123797 · TMA582635 | COLGATE-PALMOLIVE CANADA INC. | 5 Pharmaceuticals | Registered | 2003 |
| ORGAWORLD 1710426 · TMA1057158 · design | Renewi PLC | 1 Chemicals4 Oils35 Advertising+2 | Registered | 2019 |
| ORGAWORLD 1710424 · TMA1057142 | Renewi PLC | 1 Chemicals4 Oils35 Advertising+2 | Registered | 2019 |
| ORGAWORLD 1299915 · TMA740680 · design | Renewi PLC | 1 Chemicals4 Oils7 Machines+4 | Registered | 2009 |
| ORAGRAFIN 0268194 · TMA129146 | an individual | 5 Pharmaceuticals | Registered | 1962 |
| ORCARECON 2108678 · design | Orcarecon Inc. | 35 Advertising41 Education42 Science | Pending | 2021 |
| ORSERDU 2258598 · TMA1241972 · design | Owner not listed | 5 Pharmaceuticals | Registered | 2024 |
| ORSERDU 2177597 · TMA1253703 | an individual | 5 Pharmaceuticals | Registered | 2024 |
| Orzero 2081683 · TMA1202611 | Shenzhen Guoran Digital Technology Co. Ltd. | 9 Electronics | Registered | 2023 |
| OURCROWD 1844553 · TMA1104648 | Owner not shown | 35 Advertising41 Education | Registered | 2021 |
| OURCROWD 1786853 · TMA983966 | Owner not shown | 35 Advertising36 Finance | Registered | 2017 |
| ORAGUARD 1774744 · TMA1000697 | Orafol Europe GmbH | 16 Paper17 Rubber20 Furniture | Registered | 2018 |
| ORAGRAFT 1761887 · TMA983456 | an individual | 5 Pharmaceuticals | Registered | 2017 |
| ORSIRO 1677491 · TMA968393 | an individual | 2 Paints5 Pharmaceuticals10 Medical | Registered | 2017 |
| ORCHARD 1664757 · TMA918228 | Orchard Yarn and Thread Company, Inc. DBA Lion Brand Yarn Company | 23 Yarns | Registered | 2015 |
| ORCERITY 1646842 · TMA1045316 | PFIZER INC. | 5 Pharmaceuticals | Registered | 2019 |
| ORECARE 1552311 · TMA890082 · design | Tiens Group Co., Ltd. | 3 Cosmetics5 Pharmaceuticals | Registered | 2014 |
| ORGREENIC 1440885 · TMA827780 | Orgreenic, LLC | 21 Housewares | Registered | 2012 |
| ORIGRO 1343854 · TMA764363 · design | ORIGRO INC. | 35 Advertising42 Science44 Medical | Registered | 2010 |
| ORIGRO 1343853 · TMA764362 | ORIGRO INC. | 35 Advertising42 Science44 Medical | Registered | 2010 |
| ORCHARD 0728438 · TMA429707 | BLUE BANNER COMPANY, INC. (A CALIFORNIA CORPORATION) | 31 Fresh | Registered | 1994 |
| ORASURE 0691334 · TMA405936 | Orasure Technologies, Inc. (a Delaware corporation) | 10 Medical | Registered | 1992 |
| ORACORT 0563034 · TMA341845 | TARO PHARMACEUTICALS INC. | 5 Pharmaceuticals | Registered | 1988 |
| ORQRQO 2360898 | TIANCHANG SANGE TRADING CO. LTD. | 9 Electronics | Pending | 2024 |