| ONFLEX 1674548 · TMA961047 | C.R. BARD, INC. A LEGAL ENTITY | 10 Medical | Registered | 2017 |
| ONFLEX 1207454 · TMA714493 | Avient Corporation | 1 Chemicals | Registered | 2008 |
| Onfleril 2141194 · TMA1193873 | MICROBIO CO. LTD. | 5 Pharmaceuticals | Registered | 2023 |
| OneFlex 2363728 | Olympus Corporation | 10 Medical | Pending | 2024 |
| Onyflex 2241157 | neubourg invest GmbH & Co. KG | 3 Cosmetics5 Pharmaceuticals10 Medical | Pending | 2022 |
| ONFLY 2017652 | Smartek Ltd. | 9 Electronics35 Advertising | Pending | 2020 |
| ONFLY 2017651 · design | Smartek Ltd. | 9 Electronics35 Advertising | Pending | 2020 |
| ONFLOW 1985054 | Dapper Labs Inc. | 9 Electronics35 Advertising42 Science | Pending | 2019 |
| ONEPLANET 2132654 · TMA1195832 · design | CS International Trading Inc. | 21 Housewares | Registered | 2023 |
| OmniPleat 2266676 | an individual | 11 Lighting | Pending | 2023 |
| ONEFLOW 2236083 · TMA1256832 | Watts Regulator Co. | 1 Chemicals11 Lighting | Registered | 2024 |
| ONEBLADE 2232812 · TMA1243380 | an individual | 8 Hand | Registered | 2024 |
| ONEPULSE 2197785 · TMA1223224 | Startpulsing Limited | 35 Advertising42 Science | Registered | 2024 |
| ONEVALLEY 2143103 · TMA1185489 | OneValley, Inc. | 35 Advertising36 Finance41 Education+2 | Registered | 2023 |
| ONEPLUS 2126442 · TMA1221249 · design | OnePlus Technology (Shenzhen) Co. Ltd. | 18 Leather25 Clothing35 Advertising+3 | Registered | 2024 |
| OENOBIOL 2073693 · TMA1203832 | an individual | 3 Cosmetics5 Pharmaceuticals35 Advertising | Registered | 2023 |
| OMNIPAL 2071809 · TMA1201221 | an individual | 9 Electronics | Registered | 2023 |
| OMNYPULSE 2038265 · TMA1270723 | Biosense Webster, Inc. | 9 Electronics10 Medical | Registered | 2024 |
| OneFlock 2007254 · TMA1129134 | an individual | 45 Legal | Registered | 2022 |
| Omniflex 2004069 · TMA1129064 | Owner not shown | 17 Rubber20 Furniture | Registered | 2022 |
| OMNIBLONDE 2003410 · TMA1119639 · design | Owner not shown | 3 Cosmetics21 Housewares | Registered | 2022 |
| Omblastys 1984622 · TMA1099091 | Y-mAbs Therapeutics, Inc | 5 Pharmaceuticals42 Science | Registered | 2021 |
| ONEPLACE 1917019 · TMA1195057 | Trident Corporate Services (Singapore) Pte Limited as trustee for The OnePlace Unit Trust | 9 Electronics35 Advertising41 Education+1 | Registered | 2023 |
| OMPLIXIS 1909665 · TMA1100833 | an individual | 5 Pharmaceuticals | Registered | 2021 |
| OMBLIGO 1886468 · TMA1083687 | Ombligo, Inc. | 36 Finance37 Construction39 Transport+1 | Registered | 2020 |