| OntheLit | Opened | n/c | n/c | |||
| Onto | TO | Opened | n/c | n/c | ||
| Onyx Epoxy Resin | PH | Opened | n/c | n/c | ||
| Onyx Hospitality(GLOBAL) | Opened | n/c | n/c | |||
| Oobi Shoes | US | Opened | n/c | n/c | ||
| Oobli | US | Opened | n/c | n/c | ||
| ooByte | Opened | n/c | n/c | |||
| OOFOS - Creator | US | Opened | n/c | n/c | ||
| oogiebear | US | Opened | n/c | n/c | ||
| Oojo | Opened | n/c | n/c | |||
| Ooki Energy | GB | Opened | n/c | n/c | ||
| Ooma Office | Opened | n/c | n/c | |||
| Ooma Residential | Opened | n/c | n/c | |||
| Oova, Inc. | US | Opened | n/c | n/c | ||
| OPAL COOL (brand from Xena Therapies) | US | Opened | n/c | n/c | ||
| Opalescence | US | Opened | n/c | n/c | ||
| OpenArt AI | US | Opened | n/c | n/c | ||
| Open Farm | Opened | n/c | n/c | |||
| Openfit | US | Opened | n/c | n/c | ||
| Open Goaaal | Opened | n/c | n/c | |||
| Open Sky Affiliate Programme | IT | Opened | n/c | n/c | ||
| Open VPN | Opened | n/c | n/c | |||
| OphthoQuestions | US | Opened | n/c | n/c | ||
| Opiqo | AU | Opened | n/c | n/c | ||
| OPIUM | Opened | n/c | n/c | |||
| Opopop | US | Opened | n/c | n/c | ||
| OppLoans | US | Opened | n/c | n/c | ||
| OPPO ES | ES | Opened | n/c | n/c | ||
| OPPO FR | FR | Opened | n/c | n/c | ||
| OPPO India | IN | Opened | n/c | n/c | ||
| OPPO India | IN | Opened | n/c | n/c | ||
| OPPO Indonesia | ID | Opened | n/c | n/c | ||
| OPPO Indonesia | ID | Opened | n/c | n/c | ||
| OPPO Malaysia | MY | Opened | n/c | n/c | ||
| OPPO Malaysia | MY | Opened | n/c | n/c | ||
| OPPO Singapore | SG | Opened | n/c | n/c | ||
| Optimism Brand llc | Opened | n/c | n/c | |||
| OPTIMIST Botanicals | US | Opened | n/c | n/c | ||
| Options Medical Weight Loss | US | Opened | n/c | n/c | ||
| OptoPrep | Opened | n/c | n/c | |||
| OPULUS Beauty Labs | US | Opened | n/c | n/c | ||
| Opus Virtual Offices | US | Opened | n/c | n/c | ||
| Ora | Opened | n/c | n/c | |||
| Oral B DE | DE | Opened | n/c | n/c | ||
| Oral B ES | ES | Opened | n/c | n/c | ||
| Oral-B FR | FR | Opened | n/c | n/c | ||
| Oral B IT | IT | Opened | n/c | n/c | ||
| ORAL-B IT 2025 | IT | Opened | n/c | n/c | ||
| Oral B NL | NL | Opened | n/c | n/c |