| ONEPLANT 2252170 | SPARTAN CONTROLS LTD. | 9 Electronics42 Science | Pending | 2023 |
| ONEPLANET 2132654 · TMA1195832 · design | CS International Trading Inc. | 21 Housewares | Registered | 2023 |
| ONEPLACE 1917019 · TMA1195057 | Trident Corporate Services (Singapore) Pte Limited as trustee for The OnePlace Unit Trust | 9 Electronics35 Advertising41 Education+1 | Registered | 2023 |
| OMNIPLAN 1052683 · TMA588121 | an individual | 35 Advertising36 Finance37 Construction+6 | Registered | 2003 |
| ONEPLUS 2126442 · TMA1221249 · design | OnePlus Technology (Shenzhen) Co. Ltd. | 18 Leather25 Clothing35 Advertising+3 | Registered | 2024 |
| oneplus 1718910 · TMA946924 | OnePlus Technology (Shenzhen) Co. Ltd. | 3 Cosmetics18 Leather19 Building+3 | Registered | 2016 |
| ONEPLUS 1650101 · TMA978615 · design | OnePlus Technology (Shenzhen) Co. Ltd. | 9 Electronics | Registered | 2017 |
| ONEPLUS 2267969 · design | Owner not listed | 9 Electronics | Pending | 2023 |
| ONEBLADE 2232812 · TMA1243380 | an individual | 8 Hand | Registered | 2024 |
| ONEPULSE 2197785 · TMA1223224 | Startpulsing Limited | 35 Advertising42 Science | Registered | 2024 |
| ONEFLOW 2236083 · TMA1256832 | Watts Regulator Co. | 1 Chemicals11 Lighting | Registered | 2024 |
| Oneflow 1863798 · TMA1094919 | hulle24 GmbH | 9 Electronics12 Vehicles18 Leather+2 | Registered | 2021 |
| ONBELAY 1303271 · TMA687289 | ONBELAY CAPITAL INC. | 2 Paints36 Finance | Registered | 2007 |
| OneFlex 2363728 | Olympus Corporation | 10 Medical | Pending | 2024 |
| ONEPBLE 2297911 | an individual | 22 Ropes | Pending | 2023 |
| 1+ ONEPLUS 1701644 · TMA1021809 · design | OnePlus Technology (Shenzhen) Co. Ltd. | 9 Electronics14 Jewellery | Registered | 2019 |
| OMNIBLANK 1445386 · TMA807954 | CORBIN MANUFACTURING, INC. d.b.a. SYSTEM SCIENCE INSTITUTE, a legal entity | 7 Machines8 Hand | Registered | 2011 |
| OMNIPOLAR 0771401 · TMA483109 | Audio Products International Corp. | 9 Electronics | Registered | 1997 |
| OMNIPLAST 0456929 · TMA257874 | OMNIPLAST INC. | 16 Paper20 Furniture39 Transport | Registered | 1981 |
| 1+ ONEPLUS 2374618 · design | OnePlus Technology (Shenzhen) Co. Ltd. | 37 Construction | Pending | 2024 |
| OmniPleat 2266676 | an individual | 11 Lighting | Pending | 2023 |
| ONEVALLEY 2143103 · TMA1185489 | OneValley, Inc. | 35 Advertising36 Finance41 Education+2 | Registered | 2023 |
| Onfleril 2141194 · TMA1193873 | MICROBIO CO. LTD. | 5 Pharmaceuticals | Registered | 2023 |
| OENOBIOL 2073693 · TMA1203832 | an individual | 3 Cosmetics5 Pharmaceuticals35 Advertising | Registered | 2023 |
| OMNIPAL 2071809 · TMA1201221 | an individual | 9 Electronics | Registered | 2023 |