| Octopus Capital Investment Limited | Private company limited by shares | Live |
| OCTOPUS INVESTMENTS LIMITED | Private company limited by shares | Live |
| OCTOPUS KNOWLEDGE LIMITED | Private company limited by shares | Live |
| ADVANCED OCTOPUS MACHINERY COMPANY LIMITED | Private company limited by shares | Live |
| OCTOPUS NETWORK LIMITED | Private company limited by shares | Live |
| OCTOPUS NETWORK SYSTEMS LIMITED | Private company limited by shares | Dissolved |
| OPEN OCTOPUS LIMITED | Private company limited by shares | Live |
| OCTOPUS PAYMENT SYSTEMS LIMITED | Private company limited by shares | Dissolved |
| OCTOPUS PAYMENTS LIMITED | Private company limited by shares | Live |
| OCTOPUS PROJECTS LIMITED | Private company limited by shares | Live |
| OCTOPUS RESOURCES HK LIMITED | Private company limited by shares | Dissolved |
| OCTOPUS SOLUTIONS LIMITED | Private company limited by shares | Live |
| Octopus Store Limited | | Live |
| OCTOPUS SYSTEMS LIMITED | Private company limited by shares | Live |
| Octopus Transactions Limited | Private company limited by shares | Live |
| MY OCTOPUS.COM LIMITED | Private company limited by shares | Dissolved |
| OCTOPUSTRAVEL.COM (HONG KONG) LIMITED | Private company limited by shares | Live |
| OCTOPY COMPANY LIMITED | Private company limited by shares | Dissolved |
| OCTORICH LIMITED | Private company limited by shares | Live |
| OCTORIO TECHNOLOGY LIMITED | | Live |
| Octorion Capital Limited | Private company limited by shares | Live |
| OCTORYN RESOURCES LIMITED | Private company limited by shares | Live |
| OCTOSEC CPA LIMITED | Private company limited by shares | Live |
| OCTOSHAPE HONG KONG LIMITED | Private company limited by shares | Live |
| Octosoft Technology Limited | Private company limited by shares | Live |
| OCTOSPACE TRADE CO., LIMITED | Private company limited by shares | Live |
| OCTOSPAN LIMITED | Private company limited by shares | Dissolved |
| Octoton Company Limited | Private company limited by shares | Live |
| OCTOTRANS AGENCIES (HONG KONG) LIMITED | Private company limited by shares | Dissolved |
| OCTOVENT INTERNATIONAL COMPANY LIMITED | Private company limited by shares | Live Commenced dormancy on 19-Oct-2018 |
| Octovia Global Investment Limited | | Live |
| OCTOVIA MANAGEMENT LIMITED | Private company limited by shares | Live |
| OCTOWIN LIMITED | Private company limited by shares | Dissolved |
| OCTOWISE LIMITED | Private company limited by shares | Dissolved |
| OCTOWISE INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| OCTRIL LIMITED | Private company limited by shares | Live |
| OCTS Limited | Private company limited by shares | Live |
| OCTSTORE LIMITED | | Live |
| Octstudiohk Limited | Private company limited by shares | Live |
| OCTT LIMITED | | Live |
| Octus Secretaries Limited | Private company limited by shares | Live |
| Octyva Limited | Private company limited by shares | Live |
| Ocubase Limited | Private company limited by shares | Live |
| OCUHIVE LIMITED | Private company limited by shares | Live |
| Ocula HK Limited | Private company limited by shares | Live |
| OCULAR PLUS LIMITED | Private company limited by shares | Live |
| Ocular Solutions Limited | Private company limited by shares | Live |
| OCULAR SURGERY ALGORITHM LIMITED | Private company limited by shares | Live |
| OCULATUS LIMITED | Private company limited by shares | Live |
| Oculii HK Limited | Private company limited by shares | Live |
| Oculis HK, Limited | Private company limited by shares | Live |
| OCULOPLASTIC CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| Hong Kong Oculoplastic Surgery Limited | Private company limited by shares | Live |
| ST. PAUL'S OCULOPLASTIC CENTRE LIMITED | Private company limited by shares | Dissolved |
| OCULU SOLUTIONS LIMITED | Private company limited by shares | Live |
| Oculus VR HK Limited | Private company limited by shares | Live |
| Oculus Limited | Private company limited by shares | Live |
| OCUMARE TRADING LIMITED | Private company limited by shares | Live |
| Ocumension (Hong Kong) Limited | Private company limited by shares | Live |
| Ocus Limited | Private company limited by shares | Live |
| OCWEN HK LIMITED | Private company limited by shares | Live |
| OCX2 (HK) LIMITED | Private company limited by shares | Dissolved |