| OCAD 0717232 · TMA429549 | an individual | 9 Electronics | Registered | 1994 |
| OCDE 0974536 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2002 |
| OCDE 0974534 | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2002 |
| OCDE 0973195 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2013 |
| OCDE 0973039 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2011 |
| OCDE 0972362 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2008 |
| OCADU 0920791 | Ontario College of Art & Design University | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2011 |
| OCAD 0920576 | Ontario College of Art & Design University | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2011 |
| OZAWADE 2113139 · TMA1160529 | BIOPROJET EUROPE LIMITED | 5 Pharmaceuticals | Registered | 2023 |
| OESD 2192972 · TMA1219386 | Oklahoma Embroidery Supply & Design, LLC | 8 Hand9 Electronics23 Yarns+3 | Registered | 2024 |
| OUSIDE 2150242 · TMA1217303 | Shenzhen OuSiDe Technology Co. Ltd | 9 Electronics11 Lighting | Registered | 2024 |
| OKEDI 2089277 · TMA1211771 | an individual | 5 Pharmaceuticals | Registered | 2023 |
| OCTEAU 1727530 · TMA945109 | CENTRAL SPA & POOL SUPPLY LTD. | 7 Machines | Registered | 2016 |
| OCTA 1719818 · TMA1019902 | Teijin Frontier Co. Ltd. | 23 Yarns24 Textiles25 Clothing | Registered | 2019 |
| OCATA 1716992 · TMA1032595 | ASTELLAS INSTITUTE FOR REGENERATIVE MEDICINE | 5 Pharmaceuticals42 Science | Registered | 2019 |
| OSCADDIE 1696707 · TMA929827 | Appnovation Technologies Ltd. | 9 Electronics42 Science | Registered | 2016 |
| OSDE 1616911 · TMA935483 · design | Owner not shown | 35 Advertising36 Finance37 Construction+3 | Registered | 2016 |
| OSDE 0787084 · TMA490925 · design | Owner not shown | 35 Advertising36 Finance37 Construction+3 | Registered | 1998 |
| OCTA 2326230 · design | an individual | 7 Machines35 Advertising42 Science | Pending | 2024 |
| Ochido 2305863 | an individual | 28 Toys | Pending | 2024 |
| OECD 0974535 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2002 |
| OECD 0974533 | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2002 |
| OECD 0973196 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2013 |
| OECD 0973040 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2011 |
| OECD 0972360 · design | ORGANISATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT / ORGANISATION DE COOPÉRATION ET DE DÉVELOPPEMENT ÉCONOMIQUES | 1 Chemicals2 Paints3 Cosmetics+42 | Pending | 2008 |