| ONCOSNIPE 1816066 · TMA1018069 | an individual | 9 Electronics42 Science44 Medical | Registered | 2019 |
| ONCOSEC 1754816 · TMA1060749 | Oncosec Medical Incorporated | 1 Chemicals5 Pharmaceuticals | Registered | 2019 |
| ONCOSEC 1575651 · TMA1060748 | Oncosec Medical Incorporated | 10 Medical44 Medical | Registered | 2019 |
| ONCOZAC 1159531 · TMA627061 | Purapharm International (H.K.) Limited (a Hong Kong limited liability company) | 5 Pharmaceuticals | Registered | 2004 |
| ONCASPAR 0713680 · TMA449998 | SERVIER IP UK LIMITED | 5 Pharmaceuticals | Registered | 1995 |
| ONCASPAR 2297421 · design | Owner not listed | 5 Pharmaceuticals | Pending | 2023 |
| ONCOUSTICS 1610667 · TMA945598 | an individual | 9 Electronics10 Medical44 Medical | Registered | 2016 |
| ONCOASSURE 2351281 · design | OncoAssure Limited | 5 Pharmaceuticals | Pending | 2024 |
| ONCOASSURE 2351280 | OncoAssure Limited | 5 Pharmaceuticals | Pending | 2024 |
| OncoScreen 2176280 | Guangzhou Burning Rock Dx Co. Ltd. | 5 Pharmaceuticals9 Electronics10 Medical+2 | Pending | 2022 |
| ONSAGE 1956449 · TMA1191374 | PFIZER INC. | 5 Pharmaceuticals | Registered | 2023 |
| ONSAGE 1825869 · TMA1066235 | PFIZER INC. | 5 Pharmaceuticals | Registered | 2019 |
| ONCOSIM 1795765 · TMA993250 | an individual | 9 Electronics16 Paper35 Advertising+6 | Registered | 2018 |
| ONCOCAL 1698591 · TMA1045050 | OncoSil Medical Ltd. a legal entity | 5 Pharmaceuticals | Registered | 2019 |
| ONCOCRAN 1603639 · TMA915670 | an individual | 1 Chemicals5 Pharmaceuticals | Registered | 2015 |
| ONCOSEED 1039337 · TMA553395 | Medi-Physics Inc. | 10 Medical | Registered | 2001 |
| ONCOCHECK 2349431 | INOGENIX INC. | 5 Pharmaceuticals | Pending | 2024 |
| ONCOSHUTTLE 1738151 · TMA951175 | an individual | 5 Pharmaceuticals | Registered | 2016 |
| OnychoSensé 1537978 · TMA856003 | 9219-9470 QUÉBEC INC. connue sous le nom PodoSensé | 3 Cosmetics5 Pharmaceuticals | Registered | 2013 |
| OncoCompass 2180535 | Guangzhou Burning Rock Dx Co. Ltd. | 5 Pharmaceuticals9 Electronics10 Medical+2 | Pending | 2022 |
| ONCOSIGNATURE 2322081 | Acrivon Therapeutics, Inc. | 5 Pharmaceuticals44 Medical | Pending | 2024 |
| OncoShield 1756553 · TMA1064207 | Fresenius Kabi Canada Ltd. | 16 Paper17 Rubber | Registered | 2019 |
| ONCOSHIELD 1756551 · TMA1064208 · design | Fresenius Kabi Canada Ltd. | 16 Paper17 Rubber | Registered | 2019 |
| ONCOCOMPLETE 2280235 | EXACT SCIENCES CORPORATION, a legal entity | 41 Education42 Science44 Medical | Pending | 2023 |
| ONCOASSIST 2121201 | PORTABLE MEDICAL TECHNOLOGY LIMITED | 9 Electronics42 Science | Pending | 2021 |