| ORTHOCEPH 0650718 · TMA387522 | an individual | 10 Medical | Registered | 1991 |
| OrthoCare 2362519 | NAKA HERBS & VITAMINS LTD. | 5 Pharmaceuticals | Pending | 2024 |
| OrthoCan 2357312 | NAKA HERBS & VITAMINS LTD. | 5 Pharmaceuticals | Pending | 2024 |
| ORTHOCLUB 1966776 | G & H Wire Company, Inc. | 35 Advertising | Pending | 2019 |
| ORTHOSEARCH 2139810 · TMA1219761 | The British Editorial Society of Bone and Joint Surgery | 9 Electronics41 Education42 Science | Registered | 2024 |
| OrthoClinic 2309902 | NAKA HERBS & VITAMINS LTD. | 5 Pharmaceuticals | Pending | 2024 |
| ORTHOCAST 1950884 · TMA1187991 | Dr. Amit Atrey Professional Corporation | 38 Telecommunications41 Education | Registered | 2023 |
| ORTHOACCEL 1770235 · TMA975605 | ORTHOACCEL HOLDINGS, LLC | 10 Medical | Registered | 2017 |
| ORTHOACCEL 1694199 · TMA945987 | ORTHOACCEL HOLDINGS, LLC | 42 Science | Registered | 2016 |
| ORTHOCORD 1224873 · TMA701023 | Owner not shown | 10 Medical | Registered | 2007 |
| ORTHOGEL 0769208 · TMA450305 | Clinique Lafontaine Inc. | 5 Pharmaceuticals9 Electronics | Registered | 1995 |
| ORTHOCRYL 0532815 · TMA327572 | DENTAURUM GmbH & Co. KG | 1 Chemicals2 Paints5 Pharmaceuticals | Registered | 1987 |
| ORTHOCURE 0522921 · TMA307892 | an individual | 3 Cosmetics30 Coffee | Registered | 1985 |
| ORTHOSMILES 1765897 · TMA1004055 · design | ORTHOSMILES HOLDING COMPANY | 3 Cosmetics5 Pharmaceuticals9 Electronics+10 | Registered | 2018 |
| ORTHOSMILES 1765896 · TMA1004056 | ORTHOSMILES HOLDING COMPANY | 3 Cosmetics5 Pharmaceuticals9 Electronics+10 | Registered | 2018 |
| 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 |
| ORTECO 2192499 · TMA1278916 | Owner not shown | 7 Machines12 Vehicles | Registered | 2024 |
| ORTHOCOMFOOT 2191961 · TMA1254939 · design | an individual | 25 Clothing | Registered | 2024 |
| Orthogon 2011638 · TMA1199782 | Frequentis Orthogon GmbH | 9 Electronics35 Advertising37 Construction+1 | Registered | 2023 |
| ORTHOSIT 1944336 · TMA1103445 | an individual | 5 Pharmaceuticals10 Medical | Registered | 2021 |
| ORITESSE 1812684 · TMA1027024 | AbbVie Inc. | 5 Pharmaceuticals | Registered | 2019 |