| OKO 1910081 · TMA1106408 | Ecoation Innovative Solutions Inc. | 12 Vehicles | Registered | 2021 |
| OKO 1836037 · TMA1017529 | OKO Bagels Inc. | 29 Meat30 Coffee35 Advertising+1 | Registered | 2019 |
| OKO 1700175 · TMA979833 | EV Partnership Limited | 12 Vehicles | Registered | 2017 |
| OKKO 1601713 · TMA992065 · design | Limited Liability Company OKKO | 9 Electronics35 Advertising38 Telecommunications+2 | Registered | 2018 |
| OKAO 1351292 · TMA757262 · design | OMRON CORPORATION | 9 Electronics28 Toys40 Treatment+3 | Registered | 2010 |
| OKAO 1294142 · TMA737776 | OMRON CORPORATION | 9 Electronics28 Toys40 Treatment+3 | Registered | 2009 |
| OKO 0813712 · TMA492521 | KAREN'S FINE JEWELLERY INC. | 14 Jewellery35 Advertising | Registered | 1998 |
| OKO 2262483 | Owner not listed | 43 Restaurants | Pending | 2023 |
| OKKO 2060212 · design | Owner not shown | 21 Housewares29 Meat30 Coffee | Pending | 2020 |
| OAKIO 2045859 · TMA1144799 · design | Huizhou Oakio Plastic Wood Building Materials Co.Ltd | 19 Building | Registered | 2022 |
| OSOYO 1895056 · TMA1105860 | AGS FOODS CANADA LIMITED | 5 Pharmaceuticals29 Meat30 Coffee+2 | Registered | 2021 |
| OKAYA 1470122 · TMA796693 · design | Okaya Electric Industries Co. Ltd. | 9 Electronics | Registered | 2011 |
| OKIYA 1435569 · TMA768174 · design | S.D. Variations inc. | 3 Cosmetics10 Medical35 Advertising | Registered | 2010 |
| OKAYA 1366576 · TMA775325 · design | Okaya Electric Industries Co. Ltd. | 9 Electronics11 Lighting | Registered | 2010 |
| ohyeahus 2264292 · TMA1283374 | an individual | 5 Pharmaceuticals | Registered | 2025 |
| OOSSXX 2258072 · TMA1277735 · design | Shenzhenshi Xiankailike Technology Co. Ltd | 9 Electronics | Registered | 2024 |
| OKK 2256870 · TMA1276298 · design | OKK INTERNATIONAL (HONG KONG) CO. LIMITED | 34 Tobacco | Registered | 2024 |
| OKG 2254704 · TMA1273110 | Shanghai NVSMART Technology Co. Ltd. | 6 Metal9 Electronics17 Rubber | Registered | 2024 |
| OK 2253930 · TMA1273003 · design | Astral IP Enterprise Ltd. | 9 Electronics | Registered | 2024 |
| OSQ 2253155 · TMA1270254 | Owner not listed | 11 Lighting | Registered | 2024 |
| OHJA 2248120 · TMA1253153 · design | an individual | 34 Tobacco | Registered | 2024 |
| OHJA 2248116 · TMA1253152 | an individual | 34 Tobacco | Registered | 2024 |
| OQQ 2246999 · TMA1267154 | Hangzhou Tabo E-commerce Co. Ltd | 25 Clothing | Registered | 2024 |
| OiQi 2244543 · TMA1264303 | Owner not listed | 9 Electronics | Registered | 2024 |
| OSEE 2239668 · TMA1259966 · design | Osee Technology Co. Ltd. | 9 Electronics | Registered | 2024 |