| ORMUCO 1636328 · TMA925374 | Ormuco Inc. | 38 Telecommunications42 Science | Registered | 2016 |
| ORMECON 0821526 · TMA516793 | ENTHONE INC. | 1 Chemicals2 Paints9 Electronics+2 | Registered | 1999 |
| ORMIS 1465016 · TMA832649 | Prodentia Solutions inc. | 9 Electronics | Registered | 2012 |
| ORINOCO 1261182 · TMA692079 | Guittard Chocolate Company (a California corporation) | 29 Meat30 Coffee | Registered | 2007 |
| ORINOCO 1047147 · TMA596396 | Proxim Wireless Corporation | 9 Electronics35 Advertising37 Construction | Registered | 2003 |
| Orinseal 2202380 · TMA1238812 | an individual | 17 Rubber | Registered | 2024 |
| ORIONCAP 2114294 · TMA1181818 · design | Orion Cap Inc. | 36 Finance37 Construction | Registered | 2023 |
| ORIONCAP 2110805 · TMA1180564 | Orion Cap Inc. | 36 Finance37 Construction | Registered | 2023 |
| Orangelove 2050428 · TMA1166753 | an individual | 14 Jewellery | Registered | 2023 |
| ORMESA 2046711 · TMA1196374 · design | an individual | 10 Medical12 Vehicles | Registered | 2023 |
| ORANGEWOOD 1999285 · TMA1108677 · design | PRAXIS MUSICAL INSTRUMENTS, INC. | 15 Musical | Registered | 2021 |
| ORANGEWOOD 1980608 · TMA1107518 | PRAXIS MUSICAL INSTRUMENTS, INC. | 15 Musical | Registered | 2021 |
| OHRNG 1975668 · TMA1149991 | CHAUSSURES ESTRADA INC. | 25 Clothing | Registered | 2022 |
| ORANGE 1950721 · TMA1283588 | O&M Halyard International Unlimited Company | 10 Medical | Registered | 2025 |
| ORANGEPRINT 1937437 · TMA1152369 | Home Depot International, Inc. | 9 Electronics35 Advertising37 Construction+3 | Registered | 2022 |
| ORANGUTECH 1906888 · TMA1135173 | Orangutech Inc. | 35 Advertising41 Education42 Science | Registered | 2022 |
| ORANGEG 1878378 · TMA1081107 · design | Orangeg Information Technology Co. Ltd. | 7 Machines | Registered | 2020 |
| ORINSONG 1842457 · TMA1012960 · design | SHENZHEN ORINSONG TECHNOLOGY CO. LTD | 9 Electronics12 Vehicles | Registered | 2019 |
| ORANGE 1814135 · TMA1137939 | ORANGE BRAND SERVICES LIMITED | 9 Electronics14 Jewellery25 Clothing+9 | Registered | 2022 |
| ORANGE 1770296 · TMA1054145 · design | ORANGE BRAND SERVICES LIMITED | 36 Finance | Registered | 2019 |
| ORANGE 1770295 · TMA1054146 | ORANGE BRAND SERVICES LIMITED | 36 Finance | Registered | 2019 |
| Orionnuus 1736331 · TMA944457 | Services Onxiata inc. | 6 Metal9 Electronics14 Jewellery+11 | Registered | 2016 |
| ORENZ 1719199 · TMA994955 · design | an individual | 16 Paper | Registered | 2018 |
| OROMIST 1711728 · TMA1027581 | Suda Pharmaceuticals Ltd | 5 Pharmaceuticals | Registered | 2019 |
| ORANGETHEORY 1675765 · TMA911654 | OTF IP Holder, LLC | 6 Metal9 Electronics14 Jewellery+8 | Registered | 2015 |