| ONCOTERRA 2217074 · TMA1235265 | Phase Genomics, Inc. | 42 Science | Registered | 2024 |
| OMGTMD 2177941 · TMA1227273 | an individual | 6 Metal | Registered | 2024 |
| OneStock 2177427 · TMA1278840 | OneStock | 42 Science | Registered | 2024 |
| ONESAT 2170045 · TMA1204341 | Owner not shown | 9 Electronics | Registered | 2023 |
| ONSTIN 2137448 · TMA1220442 | NUTRA STANDARD INC | 5 Pharmaceuticals | Registered | 2024 |
| ownest 2133469 · TMA1196912 | Guangzhou Yunhan Xiangfeng Network Technology Co. Ltd. | 9 Electronics | Registered | 2023 |
| OnkoDisruptor 2129418 · TMA1195788 | an individual | 10 Medical | Registered | 2023 |
| ONESTREAM 2114513 · TMA1228780 | OneStream Software LLC | 9 Electronics35 Advertising41 Education+1 | Registered | 2024 |
| OMIGHTY 2108361 · TMA1139904 · design | FOKDA POPO PTE LTD | 18 Leather25 Clothing35 Advertising | Registered | 2022 |
| Omistor 2102031 · TMA1175823 | an individual | 20 Furniture | Registered | 2023 |
| ONSTAR 2095726 · TMA1250745 | Onstar LLC | 36 Finance | Registered | 2024 |
| ONESTAR 2094875 · TMA1172531 · design | Ming Shin Tools Co. Ltd. | 8 Hand | Registered | 2023 |
| OMIGHTY 2075608 · TMA1152054 · design | FOKDA POPO PTE LTD | 25 Clothing | Registered | 2022 |
| ONCOADVANCES 2068648 · TMA1280236 | American Association for Cancer Research, Inc. | 16 Paper41 Education42 Science | Registered | 2025 |
| OMIGHTY 2057600 · TMA1141400 · design | FOKDA POPO PTE LTD | 25 Clothing | Registered | 2022 |
| OMIGHTY 2056314 · TMA1139802 · design | FOKDA POPO PTE LTD | 25 Clothing | Registered | 2022 |
| OMIGHTY 2056313 · TMA1139801 · design | FOKDA POPO PTE LTD | 25 Clothing | Registered | 2022 |
| ONEXTWO 2050185 · TMA1172004 · design | AKAD General Trading LLC | 9 Electronics | Registered | 2023 |
| OMNISTORE 2038596 · TMA1250688 | TGW Logistics Group GmbH | 7 Machines9 Electronics35 Advertising+1 | Registered | 2024 |
| ONCTERNAL 2025291 · TMA1140449 | Oncternal Therapeutics, Inc. | 42 Science | Registered | 2022 |
| ONSITE 1966011 · TMA1244604 · design | Meridian International Co. Ltd. | 20 Furniture | Registered | 2024 |
| ONCOTOPIX 1946547 · TMA1230828 | Owner not shown | 9 Electronics10 Medical38 Telecommunications | Registered | 2024 |
| ONESTEM 1942613 · TMA1123998 | Mark L. Anderson and BioDivide Limited, a partnership | 5 Pharmaceuticals | Registered | 2022 |
| ONSET 1924133 · TMA1102441 | Tulsar Canada Ltd. | 9 Electronics | Registered | 2021 |
| ONESTEP 1905392 · TMA1086943 · design | Interplastic Corporation | 1 Chemicals | Registered | 2020 |