| OPTIMATRIX 1570877 · TMA909854 | American Regent, Inc. | 5 Pharmaceuticals | Registered | 2015 |
| OPTOMETRIX 0576702 · TMA345462 | ASSOCIATION PROFESSIONNELLE DES OPTOMETRISTES DU QUEBEC | 35 Advertising | Registered | 1988 |
| OPTOMEDIC 2170124 · TMA1248059 · design | Guangdong OptoMedic Technologies Inc. | 10 Medical | Registered | 2024 |
| OPTIMET 1805352 · TMA1022846 | OPTIMET CONCRETE PRODUCTS INC. a legal entity | 6 Metal19 Building | Registered | 2019 |
| OPTIMERA 1674666 · TMA915364 | an individual | 3 Cosmetics | Registered | 2015 |
| OPTIMET 1184526 · TMA615943 · design | Optimet Concrete Products Inc. | 6 Metal | Registered | 2004 |
| OPTIMER 1087960 · TMA579982 | Owner not shown | 5 Pharmaceuticals7 Machines8 Hand+3 | Registered | 2003 |
| OPTIMEDIA 0757638 · TMA451211 | PUBLICIS GROUPE SA | 35 Advertising36 Finance | Registered | 1995 |
| OPTIMINIC 0690488 · TMA440033 | Owner not shown | 5 Pharmaceuticals | Registered | 1995 |
| OPTIMER 0536602 · TMA310789 | Ecolab USA, Inc. | 1 Chemicals | Registered | 1986 |
| OPTIMER 2349254 · design | Owner not listed | 5 Pharmaceuticals42 Science44 Medical | Pending | 2024 |
| OPTIMEDIA 2308524 | an individual | 19 Building | Pending | 2024 |
| OPTIMEDIA 2308523 | an individual | 6 Metal | Pending | 2024 |
| OPTIMARIS 2265496 | an individual | 1 Chemicals | Pending | 2023 |
| OPTIMEDICAL 1359374 · TMA775230 · design | IDEXX LABORATORIES, INC. | 10 Medical | Registered | 2010 |
| Optime 2208243 · TMA1280840 | an individual | 6 Metal7 Machines26 Sewing | Registered | 2025 |
| OptimalRx 2200001 · TMA1238488 | an individual | 44 Medical | Registered | 2024 |
| OptiMicro 2081705 · TMA1166983 | OptiMicro Technologies, Inc. | 42 Science | Registered | 2023 |
| OPTIMI 2051920 · TMA1217931 | Optimi Health Corp. | 1 Chemicals5 Pharmaceuticals30 Coffee+1 | Registered | 2024 |
| optimel 2002380 · TMA1155956 | Melcare Medical Pty Ltd | 5 Pharmaceuticals | Registered | 2022 |
| OPTIMAIRO 1901547 · TMA1132486 · design | CATA Deutschland GmbH | 6 Metal11 Lighting17 Rubber+2 | Registered | 2022 |
| optimAIRo 1858915 · TMA1078708 | CATA Deutschland GmbH | 6 Metal11 Lighting17 Rubber+2 | Registered | 2020 |
| OPTIMELT 1832905 · TMA1022757 | PRAXAIR TECHNOLOGY, INC. | 37 Construction41 Education42 Science | Registered | 2019 |
| Optimat 1756862 · TMA955027 | MATELAS RENE INC. | 20 Furniture | Registered | 2016 |
| OPTIME 1711780 · TMA1042215 | CENTRE HOSPITALIER UNIVERSITAIRE SAINTE-JUSTINE | 44 Medical | Registered | 2019 |