| OPTIONAL 2017976 · TMA1267867 · design | an individual | 25 Clothing | Registered | 2024 |
| OPTIONS 1768232 · TMA979026 | Handi-Craft Company | 10 Medical | Registered | 2017 |
| OPTIONFIT 1751559 · TMA992924 | McKesson Canada Corporation | 35 Advertising38 Telecommunications | Registered | 2018 |
| OPTIONS 1661306 · TMA914169 · design | an individual | 35 Advertising36 Finance37 Construction+1 | Registered | 2015 |
| OPTIONFLEX 1531196 · TMA879660 | Kia Canada Inc. | 36 Finance39 Transport | Registered | 2014 |
| OPTIONS 1518016 · TMA849344 | Canadian Tire Corporation, Limited | 35 Advertising | Registered | 2013 |
| OPTIONS 1354537 · TMA728486 | an individual | 35 Advertising41 Education45 Legal | Registered | 2008 |
| OPTIONS 1177391 · TMA624911 | Groupe Lacasse Inc. | 20 Furniture | Registered | 2004 |
| OPTIONS 0866359 · TMA508427 | Mohawk Fine Papers Inc. | 3 Cosmetics8 Hand13 Firearms+2 | Registered | 1999 |
| OPTIONS 0857452 · TMA564437 | Medavie Inc. | 36 Finance44 Medical | Registered | 2002 |
| OPTIONS 0777252 · TMA466383 | Canadian Tire Corporation, Limited | 36 Finance | Registered | 1996 |
| OPTIONS 0776855 · TMA467979 | Batesville Services, LLC (an Indiana limited liability company) | 20 Furniture | Registered | 1996 |
| OPTIONS 0722990 · TMA429984 | Canadian Tire Corporation, Limited | 35 Advertising | Registered | 1994 |
| OPTIONS 0715823 · TMA423828 | Canadian Tire Corporation, Limited | 35 Advertising | Registered | 1994 |
| OPTIONS 0713613 · TMA425030 · design | Canadian Tire Corporation, Limited | 35 Advertising | Registered | 1994 |
| OPTIONS 0613292 · TMA448475 | 171415 Canada Inc. | 25 Clothing | Registered | 1995 |
| OPTIONS 0593741 · TMA347740 | OAKLEY, INC. | 9 Electronics | Registered | 1988 |
| OPTIONSTATION 0824437 · TMA480303 | TradeStation Technologies, Inc. (a Florida corporation) | 9 Electronics | Registered | 1997 |
| OPTIONFINDER 0598356 · TMA359133 | Option Technologies Interactive, LLC (a Florida limited liability company) | 9 Electronics | Registered | 1989 |
| OptionsDepth 2333534 | 9362-8519 Quebec Inc. | 9 Electronics35 Advertising36 Finance+2 | Pending | 2024 |
| OPTIMALIST 2210401 · TMA1241783 | Opscotch Canada Inc. | 18 Leather21 Housewares24 Textiles+1 | Registered | 2024 |
| OPTINAND 2161450 · TMA1266838 | Western Digital Technologies, Inc. | 9 Electronics | Registered | 2024 |
| OptiOne 2151401 · TMA1185608 | Liebel-Flarsheim Company LLC | 10 Medical | Registered | 2023 |
| OPTIWINE 1833612 · TMA1019155 | an individual | 21 Housewares | Registered | 2019 |
| OPTIWINE 1833611 · TMA1019154 · design | an individual | 21 Housewares | Registered | 2019 |