| ONELINK 1880411 · TMA1130413 | BRK BRANDS, INC. | 9 Electronics28 Toys | Registered | 2022 |
| ONELINK 1788275 · TMA1019890 | Legrand AV Inc. | 9 Electronics | Registered | 2019 |
| ONELAND 1786595 · TMA985615 | MARKARE COMPANY, LLC | 41 Education | Registered | 2017 |
| ONELINK 1702435 · TMA923843 | BRK BRANDS, INC. | 9 Electronics28 Toys | Registered | 2015 |
| ONELINK 1274381 · TMA691325 | BRK BRANDS, INC. | 9 Electronics | Registered | 2007 |
| Omeland 1808377 · TMA1089391 | an individual | 9 Electronics42 Science | Registered | 2020 |
| OUMILAN 2260834 · TMA1279526 · design | an individual | 14 Jewellery | Registered | 2024 |
| ONLUME 2182272 · TMA1211384 | ONLUME INC. | 10 Medical | Registered | 2023 |
| ONLINEORGANICS 2080070 · TMA1166926 · design | 12590140 CANADA INC. | 35 Advertising | Registered | 2023 |
| Onlinesity 2028592 · TMA1134971 | an individual | 35 Advertising | Registered | 2022 |
| Omilion 2011319 · TMA1131103 | Zheng Zhou OHOH Information Technology Co.Ltd | 24 Textiles25 Clothing | Registered | 2022 |
| ONLAND 1816992 · TMA1002789 | Teranet Inc. | 38 Telecommunications | Registered | 2018 |
| ONLINEOFFICE 1621124 · TMA897518 | Century 21 Real Estate LLC | 36 Finance | Registered | 2015 |
| ONLINESHOES 1618437 · TMA931457 | Onlineshoes.com Inc. | 18 Leather25 Clothing35 Advertising | Registered | 2016 |
| ONLANE 1517123 · TMA818251 | OpenLane, Inc. | 35 Advertising36 Finance37 Construction+3 | Registered | 2012 |
| ONLINER 1119303 · TMA581901 | High Liner Foods Incorporated | 9 Electronics | Registered | 2003 |
| ONLINE 1043952 · TMA575337 | NIKON OPTICAL CANADA INC. | 9 Electronics | Registered | 2003 |
| ONLIWON 0992189 · NFLD2189 | CONSOLIDATED CELLULOSE PRODUCTS, INC. (A NEW HAMPSHIRE CORPORATION) | 16 Paper | Registered | 1936 |
| OMNILINK 0685223 · TMA512637 | OMNI Name Company | 9 Electronics37 Construction42 Science+1 | Registered | 1999 |
| ONLIWON 0484284 · TMDA25988 | Kruger Products Inc. | 16 Paper21 Housewares | Registered | 1920 |
| OMOLENE 0387912 · TMA214711 | CAN TECHNOLOGIES, INC. | 5 Pharmaceuticals31 Fresh | Registered | 1976 |
| ONLIWON 0069486 · TMDA14582 | Kruger Products Inc. | 16 Paper21 Housewares | Registered | 1910 |
| ONLYNEWS 2373186 | 12557142 Canada Inc. | 41 Education | Pending | 2025 |
| ONLYWINS 2342495 | YGGDRASIL MALTA LIMITED | 9 Electronics28 Toys41 Education+1 | Pending | 2024 |
| Onelinkmore 2313491 | an individual | 9 Electronics | Pending | 2024 |