| opsplot 2106504 · TMA1211857 | OPSPLOT CO. LTD. | 42 Science | Registered | 2023 |
| OPUSWAVE 2239469 · TMA1262890 | Owner not listed | 10 Medical | Registered | 2024 |
| OPAXVIZ 2193036 · TMA1217665 | BIOGEN MA INC. | 5 Pharmaceuticals | Registered | 2024 |
| OFKPO 2178337 · TMA1228186 | an individual | 28 Toys | Registered | 2024 |
| ofsbly 2087798 · TMA1168826 | SUNYEAR TRADING COMPANY | 9 Electronics | Registered | 2023 |
| ofsbly 2087796 · TMA1168825 | SUNYEAR TRADING COMPANY | 11 Lighting | Registered | 2023 |
| OVHspirit 1893825 · TMA1098927 | OVH | 9 Electronics35 Advertising36 Finance+5 | Registered | 2021 |
| OFKP 1823297 · TMA998380 · design | Shenzhen Enzege Technology Co. Ltd. | 9 Electronics | Registered | 2018 |
| Offspring 1811227 · TMA1060731 | Canyon Bicycles GmbH | 12 Vehicles | Registered | 2019 |
| OPJEFTI 1794158 · TMA1046334 | BRISTOL-MYERS SQUIBB COMPANY (A DELAWARE CORPORATION) | 5 Pharmaceuticals | Registered | 2019 |
| OFFICEVIBE 1766684 · TMA989047 | Plateforme Workleap inc. | 42 Science | Registered | 2018 |
| OEUFSpresto !! 1759209 · TMA988771 | BURNBRAE FARMS LIMITED | 29 Meat | Registered | 2018 |
| OBSEV 1741166 · TMA981275 | Shandy Media, Inc. | 35 Advertising41 Education43 Restaurants+2 | Registered | 2017 |
| OPSBA 1678339 · TMA914988 | ONTARIO PUBLIC SCHOOL BOARDS' ASSOCIATION | 6 Metal14 Jewellery16 Paper+8 | Registered | 2015 |
| OFFSPRING 1675886 · TMA989106 | Mamiye IP Holdings LLC | 25 Clothing | Registered | 2018 |
| OfficeApp 1657952 · TMA936999 | Owner not shown | 9 Electronics42 Science45 Legal | Registered | 2016 |
| OFFICEBYME 1655966 · TMA1043236 | an individual | 9 Electronics16 Paper35 Advertising+3 | Registered | 2019 |
| OFFSPRING 1402715 · TMA754426 | COOKE AQUACULTURE, INC. | 35 Advertising40 Treatment42 Science+1 | Registered | 2009 |
| OFFICEPRO 1385772 · TMA756431 | KEURIG GREEN MOUNTAIN, INC. | 7 Machines | Registered | 2010 |
| OBUSFORME 1049074 · TMA560640 · design | HoMedics USA, LLC | 5 Pharmaceuticals9 Electronics10 Medical+5 | Registered | 2002 |
| OBUSFORME 1025051 · TMA546935 | HoMedics USA, LLC | 5 Pharmaceuticals9 Electronics10 Medical+5 | Registered | 2001 |
| OPASPRAY 0467931 · TMA271521 | BPSI Holdings LLC | 2 Paints30 Coffee | Registered | 1982 |
| OPUS4PLUS 2315634 | an individual | 35 Advertising39 Transport42 Science | Pending | 2024 |
| OPUSVI 2296453 | Owner not listed | 41 Education | Pending | 2023 |
| OFFICEPlex 2281313 | Black Diamond Limited Partnership | 19 Building37 Construction | Pending | 2023 |