| OVERCLOCKED 1912897 · TMA1097466 | Apollo Brands LLC | 30 Coffee | Registered | 2021 |
| OVERJET 2149608 · TMA1188752 | Overjet Inc | 42 Science | Registered | 2023 |
| OVERCAST 2085480 · TMA1209533 | Overcast Innovations LLC | 6 Metal11 Lighting19 Building+1 | Registered | 2023 |
| OVERCAST 1892083 · TMA1073637 | Plateforme Workleap inc. | 42 Science | Registered | 2020 |
| OVERSIGHT 1528570 · TMA827322 | GRIDDLY GAMES INC. | 28 Toys | Registered | 2012 |
| OVERSTONE 1323945 · TMA753286 · design | Booster Wine Group Limited Partneship | 33 Wine | Registered | 2009 |
| OVERSTONE 1323943 · TMA753416 | Booster Wine Group Limited Partneship | 33 Wine | Registered | 2009 |
| OVERSEA 2278235 | ABB Asea Brown Boveri Ltd. | 9 Electronics35 Advertising37 Construction+2 | Pending | 2023 |
| OVERSITE 2069466 | HPX Media Inc. | 42 Science | Pending | 2020 |
| OVERSTATE 1964491 · design | Owner not shown | 25 Clothing | Pending | 2019 |
| OPERIX 2213294 · TMA1233925 | IFS Enterprises, LLC | 42 Science | Registered | 2024 |
| OBERICOL 2200913 · TMA1237675 | an individual | 20 Furniture | Registered | 2024 |
| OVERSEADIA 2173032 · TMA1277386 · design | BAIDU ONLINE NETWORK TECHNOLOGY (BEIJING) CO. LTD. | 9 Electronics35 Advertising36 Finance+2 | Registered | 2024 |
| OpreX 2106659 · TMA1210722 | YOKOGAWA ELECTRIC CORPORATION | 45 Legal | Registered | 2023 |
| OPIRG 2010761 · TMA1129830 | Owner not shown | 35 Advertising36 Finance41 Education | Registered | 2022 |
| Opereason 1943075 · TMA1167327 | Opereason Analytics Inc. | 42 Science | Registered | 2023 |
| OPERSYS 1940548 · TMA1149775 | Opersys inc. | 41 Education42 Science | Registered | 2022 |
| OpreX 1916199 · TMA1132434 | YOKOGAWA ELECTRIC CORPORATION | 9 Electronics35 Advertising37 Construction+1 | Registered | 2022 |
| Overoceans 1896420 · TMA1072669 | Owner not shown | 3 Cosmetics5 Pharmaceuticals | Registered | 2020 |
| OPERIS 1890267 · TMA1105442 | Operis Group Plc | 9 Electronics16 Paper35 Advertising+3 | Registered | 2021 |
| OBERYZ 1869296 · TMA1063542 | Owner not shown | 5 Pharmaceuticals | Registered | 2019 |
| OFFERSIGN 1853124 · TMA1014784 | OfferSign Incorporated | 38 Telecommunications42 Science | Registered | 2019 |
| OVERCOATS 1796701 · TMA1047615 | 20/20 MARKETING LTD. | 3 Cosmetics9 Electronics21 Housewares+1 | Registered | 2019 |
| OBRIZANDA 1710854 · TMA1033283 | GLAXO GROUP LIMITED | 5 Pharmaceuticals44 Medical | Registered | 2019 |
| OVERCZ 1702694 · TMA948592 · design | Les Industries Arctic North Inc. | 25 Clothing | Registered | 2016 |