| OOPS!!!!!! 1881762 · TMA1088230 | R & D HYGIENE SOLUTIONS INC. | 5 Pharmaceuticals25 Clothing | Registered | 2020 |
| OOPS 1305516 · TMA740630 | an individual | 33 Wine | Registered | 2009 |
| OOPS!! 0819296 · TMA480467 · design | Intercontinental Great Brands LLC | 30 Coffee | Registered | 1997 |
| OOPS!! 0643934 · TMA430097 · design | BCP IV Service Station LP | 21 Housewares25 Clothing35 Advertising+1 | Registered | 1994 |
| OPS 2197953 · TMA1222496 | X-Naut, LLC | 9 Electronics | Registered | 2024 |
| OVOS 1903984 · TMA1106902 | SHANGHAI DUCO NETWORK TECHNOLOGY CO. LTD | 9 Electronics21 Housewares | Registered | 2021 |
| OOFOS 1691038 · TMA918588 | Oofos, Inc. | 25 Clothing | Registered | 2015 |
| OVOS 1384172 · TMA747652 | Ovos Natural Health Inc. | 5 Pharmaceuticals35 Advertising40 Treatment+2 | Registered | 2009 |
| OUAPS 1301945 · TMA698521 | SILVERLIT LTD. | 9 Electronics28 Toys | Registered | 2007 |
| OOFOS 2358131 · design | Oofos, Inc. | 10 Medical25 Clothing | Pending | 2024 |
| OPS 0971242 | an individual | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2000 |
| OPS 0971240 | Owner not shown | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2000 |
| OOFIS 0916171 · design | Ontario Infrastructure Projects Corporation | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2005 |
| OOFIS 0916170 | Ontario Infrastructure Projects Corporation | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2005 |
| OVVGO 2236382 · TMA1258127 | an individual | 11 Lighting | Registered | 2024 |
| OFIG 2224243 · TMA1250025 | an individual | 12 Vehicles | Registered | 2024 |
| OPPOSHE 2217317 · TMA1246695 | an individual | 18 Leather | Registered | 2024 |
| ohbox 2214336 · TMA1244381 | Shenzhen Pintai Pet Supplies Co., Ltd. | 9 Electronics | Registered | 2024 |
| OPAGE 2205609 · TMA1241349 | Guangzhou Haokun E-Commerce Co., Ltd. | 18 Leather | Registered | 2024 |
| OVS4U 2203838 · TMA1239962 | Xiamen Kualaikuaqu E-Commerce Co., Ltd. | 24 Textiles | Registered | 2024 |
| OVICCI 2179824 · TMA1228997 | an individual | 10 Medical | Registered | 2024 |
| OVEGE 3 2174289 · TMA1269772 | Natural Life Nutrition Inc. | 1 Chemicals5 Pharmaceuticals | Registered | 2024 |
| ovichi 2172588 · TMA1222386 | Suzhou Ruianmei Trading Co. Ltd. | 25 Clothing | Registered | 2024 |
| Obosoyo 2172367 · TMA1278806 | an individual | 25 Clothing | Registered | 2024 |
| Ovis 2159306 · TMA1218419 | Olds Softgels Inc. | 1 Chemicals3 Cosmetics5 Pharmaceuticals+5 | Registered | 2024 |