| OMEGAPLEX 1685047 · TMA921559 | CERPUR Pioneer, LLC | 5 Pharmaceuticals | Registered | 2015 |
| OMEGAPURE 1413565 · TMA758215 | OMEGA PROTEIN, INC. a legal entity | 5 Pharmaceuticals | Registered | 2010 |
| OMEGAPET 1131754 · TMA606226 · design | Omega Nutrition Canada Inc. | 5 Pharmaceuticals31 Fresh | Registered | 2004 |
| OMEGAPURE 1076424 · TMA568915 | OMEGA PROTEIN, INC. a legal entity | 5 Pharmaceuticals29 Meat | Registered | 2002 |
| OMEGAFORCE 1905664 · TMA1091089 | Amazon Technologies, Inc. | 5 Pharmaceuticals | Registered | 2021 |
| OMEGABLUE 1451236 · TMA843783 | an individual | 1 Chemicals3 Cosmetics5 Pharmaceuticals | Registered | 2013 |
| OmegaVEG 1416762 · TMA811167 | Assured Natural Distribution Inc. | 5 Pharmaceuticals | Registered | 2011 |
| OmegaPro-3 1374614 · TMA765430 | Can-Vet Animal Health Supplies Ltd. | 5 Pharmaceuticals | Registered | 2010 |
| OmegaFlex 1349087 · TMA764091 | Omega Flex, Inc. (Corporation organized under the laws of the State of Pennsylvania) | 6 Metal11 Lighting | Registered | 2010 |
| OMEGAVITE 1067837 · TMA568282 | CANOMEGA INDUSTRIES INC. | 5 Pharmaceuticals | Registered | 2002 |
| OMOOSPACE 2210855 · TMA1226378 | Studio Grand Design Inc. | 9 Electronics | Registered | 2024 |
| oncoflake 2183708 · TMA1229630 | Oncoradiomics | 9 Electronics42 Science44 Medical | Registered | 2024 |
| OMNISHOP 2169237 · TMA1282577 | Cloud Drop Technologies LLC | 9 Electronics14 Jewellery16 Paper+7 | Registered | 2025 |
| ONCOBIX 2146652 · TMA1228857 · design | ONCOBIX CO., LTD. | 5 Pharmaceuticals | Registered | 2024 |
| ONESHOP 2144537 · TMA1201685 · design | Inventory Systems Inc. | 42 Science45 Legal | Registered | 2023 |
| ONESPORT 2119011 · TMA1186396 · design | Dongguan onesport Technology Co. Ltd | 12 Vehicles | Registered | 2023 |
| ONCOPREX 2089152 · TMA1214024 | Genprex, Inc. | 5 Pharmaceuticals | Registered | 2023 |
| OMGEVI 2089065 · TMA1196487 | Theravance Biopharma Ireland Limited | 5 Pharmaceuticals | Registered | 2023 |
| OMNISPEND 2081260 · TMA1150613 | Market Track, LLC | 9 Electronics35 Advertising42 Science | Registered | 2022 |
| OMNICEPT 2060646 · TMA1278414 | Hewlett-Packard Development Company, L.P. | 9 Electronics | Registered | 2024 |
| ONECABLE 2036998 · TMA1270704 | an individual | 9 Electronics | Registered | 2024 |
| ONECABLE 2036997 · TMA1270703 · design | an individual | 9 Electronics | Registered | 2024 |
| ONCOPEPTIDES 2033388 · TMA1227653 | an individual | 1 Chemicals5 Pharmaceuticals42 Science | Registered | 2024 |
| OncoFreeze 1942178 · TMA1159644 | Siemens Medical Solutions USA, Inc. | 9 Electronics | Registered | 2023 |
| ONCOVANT 1939566 · TMA1125507 | Roivant Sciences GmbH | 5 Pharmaceuticals42 Science44 Medical | Registered | 2022 |