| ORTECH 1461764 · TMA806127 | Ortech Industries Inc. | 9 Electronics11 Lighting17 Rubber+1 | Registered | 2011 |
| ORTECH 0907719 | an individual | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 1996 |
| ORTECH 0906157 | an individual | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 1993 |
| ORTECO 2192499 · TMA1278916 | Owner not shown | 7 Machines12 Vehicles | Registered | 2024 |
| ORTEC 0337078 · TMA179175 | Advanced Measurement Technology, Inc. | 9 Electronics16 Paper | Registered | 1971 |
| ORTUSTECH 1469014 · TMA842356 | TOPPAN Holdings Inc. | 9 Electronics11 Lighting | Registered | 2013 |
| ORATEX 1740884 · TMA961014 | an individual | 1 Chemicals16 Paper17 Rubber | Registered | 2017 |
| ORTEGA 1651033 · TMA1009417 | B&G FOODS NORTH AMERICA, INC. a legal entity | 29 Meat30 Coffee | Registered | 2018 |
| ORTEGA 1651028 · TMA1064359 · design | B&G FOODS NORTH AMERICA, INC. a legal entity | 30 Coffee | Registered | 2019 |
| ORTEGA 0266790 · TMA127156 | B&G FOODS NORTH AMERICA, INC. | 29 Meat30 Coffee | Registered | 1962 |
| "ORTAC" 0204692 · UCA34996 | ContiTech Canada, Inc. | 17 Rubber | Registered | 1949 |
| ORTEGA 2039730 · design | B&G FOODS NORTH AMERICA, INC. a legal entity | 29 Meat30 Coffee | Pending | 2020 |
| ORTEGA 2039728 · design | B&G FOODS NORTH AMERICA, INC. a legal entity | 29 Meat30 Coffee | Pending | 2020 |
| Ouritsu 2248039 · TMA1267258 | Owner not listed | 20 Furniture | Registered | 2024 |
| Ortsoon 2245277 · TMA1264389 | Huizhou Xinxiao Network Technology Co. Ltd | 21 Housewares | Registered | 2024 |
| ORTHUS 2240319 · TMA1234028 | DYZE DESIGN INC. | 9 Electronics | Registered | 2024 |
| ORDSPONO 2210806 · TMA1244178 | REGENERON PHARMACEUTICALS, INC. | 5 Pharmaceuticals | Registered | 2024 |
| ORTIZAN 2207899 · TMA1274242 · design | an individual | 9 Electronics | Registered | 2024 |
| ORTHOCOMFOOT 2191961 · TMA1254939 · design | an individual | 25 Clothing | Registered | 2024 |
| ORTHOSEARCH 2139810 · TMA1219761 | The British Editorial Society of Bone and Joint Surgery | 9 Electronics41 Education42 Science | Registered | 2024 |
| Orthogon 2011638 · TMA1199782 | Frequentis Orthogon GmbH | 9 Electronics35 Advertising37 Construction+1 | Registered | 2023 |
| ORTHOCAST 1950884 · TMA1187991 | Dr. Amit Atrey Professional Corporation | 38 Telecommunications41 Education | Registered | 2023 |
| ORTHOSIT 1944336 · TMA1103445 | an individual | 5 Pharmaceuticals10 Medical | Registered | 2021 |
| ORITESSE 1812684 · TMA1027024 | AbbVie Inc. | 5 Pharmaceuticals | Registered | 2019 |
| ORTHOACCEL 1770235 · TMA975605 | ORTHOACCEL HOLDINGS, LLC | 10 Medical | Registered | 2017 |