| ORCINUS 2348941 · design | Enesty GmbH | 7 Machines9 Electronics11 Lighting | Pending | 2024 |
| ORACING 2061170 · design | Sunrise Medical (US) LLC | 12 Vehicles28 Toys35 Advertising | Pending | 2020 |
| ORCAN 1893775 · TMA1102312 | an individual | 7 Machines9 Electronics11 Lighting+1 | Registered | 2021 |
| ORCON 1278610 · TMA687963 · design | Biologische Insel Lothar Moll GmbH & Co. KG | 1 Chemicals8 Hand17 Rubber | Registered | 2007 |
| ORKIN 0688276 · TMA471452 · design | ORKIN EXPANSION, INC. | 37 Construction41 Education | Registered | 1997 |
| ORKIN 0688260 · TMA470965 | ORKIN EXPANSION, INC. | 37 Construction41 Education | Registered | 1997 |
| ORIGINS 2242991 · TMA1258449 | ORIGINS NATURAL RESOURCES INC. | 9 Electronics | Registered | 2024 |
| ORGANIA 2022498 · TMA1187029 | an individual | 29 Meat31 Fresh32 Beer | Registered | 2023 |
| ORGANIA 2022493 · TMA1188085 · design | an individual | 31 Fresh | Registered | 2023 |
| ORIGINS 1875632 · TMA1070633 | Croll & Co. Ltd. | 45 Legal | Registered | 2020 |
| ORIGINS 1856608 · TMA1041840 | Anchor Wall Systems Limited, (a Delaware Corporation) | 19 Building | Registered | 2019 |
| ORIGINE 1694523 · TMA918849 | POMDIAL INC. | 33 Wine | Registered | 2015 |
| ORIGINS 1663593 · TMA1046299 | ORIGINS NATURAL RESOURCES INC. | 21 Housewares | Registered | 2019 |
| ORGANIC 1565018 · TMA884512 | an individual | 11 Lighting | Registered | 2014 |
| ORIGINS 1535725 · TMA827428 | BENJAMIN MOORE & CO. LIMITED | 2 Paints | Registered | 2012 |
| ORIGINE 1470562 · TMA857526 | ORIGINE BISTRO INC. | 43 Restaurants | Registered | 2013 |
| ORGANIX 1371808 · TMA866044 | JNTL Consumer Health I (Switzerland) GmbH | 3 Cosmetics | Registered | 2013 |
| ORGANIC 1336788 · TMA802406 · design | Owner not shown | 9 Electronics28 Toys35 Advertising+2 | Registered | 2011 |
| OriginO 1318729 · TMA781612 | Origin Organic Farms, Inc. | 31 Fresh35 Advertising | Registered | 2010 |
| ORIGINS 1179691 · TMA617049 | ORIGINS NATURAL RESOURCES INC. | 35 Advertising44 Medical | Registered | 2004 |
| ORIGINS 1137539 · TMA635048 | Premier Tech Ltée/Premier Tech Ltd. | 1 Chemicals3 Cosmetics5 Pharmaceuticals+8 | Registered | 2005 |
| ORIGINS 1110923 · TMA671402 · design | ORIGINS NATURAL RESOURCES INC. | 35 Advertising44 Medical | Registered | 2006 |
| ORIGINS 1110922 · TMA671380 | ORIGINS NATURAL RESOURCES INC. | 35 Advertising44 Medical | Registered | 2006 |
| ORGANIC 1039967 · TMA556919 · design | FERTI TECHNOLOGIES INC. | 1 Chemicals | Registered | 2002 |
| ORIGINS 0876557 · TMA518092 | ORIGINS NATURAL RESOURCES INC. | 35 Advertising41 Education | Registered | 1999 |