| OPELLO 2138771 · TMA1214242 | an individual | 5 Pharmaceuticals | Registered | 2023 |
| OPALE 1941451 · TMA1213706 | Owner not shown | 1 Chemicals40 Treatment42 Science | Registered | 2023 |
| OPLI 1812360 · TMA998948 | an individual | 18 Leather | Registered | 2018 |
| OBLO 1665034 · TMA1033155 | Owner not shown | 11 Lighting | Registered | 2019 |
| OPPLE 1658143 · TMA922925 · design | Opple Lighting Co. Ltd. | 6 Metal7 Machines9 Electronics+2 | Registered | 2015 |
| OPHLO 1619750 · TMA898811 | Best Environmental Technologies Inc. | 32 Beer | Registered | 2015 |
| OPPLE 1604380 · TMA933130 · design | Opple Lighting Co. Ltd. | 9 Electronics11 Lighting | Registered | 2016 |
| OBLO 1472670 · TMA845278 | Owner not shown | 28 Toys | Registered | 2013 |
| OPALE 1423722 · TMA834940 | Owner not shown | 9 Electronics38 Telecommunications42 Science | Registered | 2012 |
| OPEL 0553547 · TMA327650 · design | OAK PARK ENTERPRISES LTD. | 6 Metal8 Hand9 Electronics+1 | Registered | 1987 |
| OPEL 0275111 · TMA144802 | Opel Automobile GmbH | 7 Machines9 Electronics11 Lighting+5 | Registered | 1966 |
| OPL5 2335746 | GUANGZHOU FIVEPLUS TECHNOLOGY CO.LIMITED | 9 Electronics | Pending | 2024 |
| OPPLE 2225478 · design | Opple Lighting Co. Ltd. | 35 Advertising | Pending | 2022 |
| OPEEL 2147546 | an individual | 21 Housewares25 Clothing35 Advertising | Pending | 2021 |
| OPOULE 2043987 · TMA1182418 | REA Innovations, Inc. | 3 Cosmetics | Registered | 2023 |
| OPFEEL 1955742 · TMA1184511 | PROJETCLUB, SA | 9 Electronics18 Leather25 Clothing+1 | Registered | 2023 |
| ohplay 1907109 · TMA1127897 | SHENZHEN AIRSMART TECHNOLOGY CO. LTD | 9 Electronics35 Advertising38 Telecommunications+1 | Registered | 2022 |
| OPALIA 1814309 · TMA1065015 | Bains Ultra inc. | 11 Lighting | Registered | 2019 |
| OPIELA 1533182 · TMA854779 | JAMP PHARMA CORPORATION | 25 Clothing | Registered | 2013 |
| OFFLEY 0636233 · TMA378856 · design | an individual | 33 Wine | Registered | 1991 |
| OPELLA 2322009 | an individual | 3 Cosmetics5 Pharmaceuticals9 Electronics+3 | Pending | 2023 |
| OPELLA 2296991 | an individual | 35 Advertising42 Science | Pending | 2023 |
| OPALIA 2137637 | BetterMilk Inc. | 1 Chemicals9 Electronics29 Meat+2 | Pending | 2021 |