| OpenST Limited | Company limited by guarantee | Live |
| OpenStack Limited | Private company limited by shares | Live |
| OPENSTAR COMPANY LIMITED | Private company limited by shares | Dissolved |
| OPENSTRAT LIMITED | Private company limited by shares | Live |
| DDC OpenStudio Media Limited | Private company limited by shares | Live |
| OPENTECH LIMITED | Private company limited by shares | Dissolved |
| OPENTECH LIMITED | Private company limited by shares | Dissolved |
| OPENTECH DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| OPENTECH (INTERNATIONAL) LIMITED | Private company limited by shares | Live |
| OPENTECH INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| Opentech Technology Limited | Private company limited by shares | Live |
| OpenTechno Limited | Private company limited by shares | Live |
| OPENTEK LIMITED | | Live |
| OPENTEL GROUP LIMITED | Private company limited by shares | Dissolved |
| OPENTELL TRADING & INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| OPENTIDE LIMITED | Private company limited by shares | Dissolved |
| OPENTIDE INVESTMENTS LIMITED | Private company limited by shares | Live |
| OPENTIVE COMPANY LIMITED | Private company limited by shares | Dissolved |
| Opentown Internet HK Limited | Private company limited by shares | Live |
| OPENTRADE LIMITED | Private company limited by shares | Live |
| OPEN-TRADE.NET LIMITED | Private company limited by shares | Dissolved |
| Opentrey Limited | Private company limited by shares | Live |
| Opentrons Labworks HK Inc. Limited | Private company limited by shares | Live |
| OPENTTON INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| Openup Group Company Limited | Private company limited by shares | Live |
| HK OPENUP TRAVEL CO., LIMITED | Private company limited by shares | Live |
| openUU Limited | Private company limited by shares | Live |
| OPENVENTURE COMPANY LIMITED | Private company limited by shares | Dissolved |
| Openverse Limited | | Live |
| OPENVESTED LIMITED | Private company limited by shares | Live |
| OPENVIEW COMPANY LIMITED | Private company limited by shares | Dissolved |
| OPENVIEW LIMITED | Private company limited by shares | Dissolved |
| OPENVIEW SERVICE LIMITED | Private company limited by shares | Live |
| OpenVino Company Limited | Private company limited by shares | Live |
| Openvision Limited | Private company limited by shares | Live |
| OPENVOX COMMUNICATION (HONGKONG) CO., LIMITED | Private company limited by shares | Live |
| OPENWAY LIMITED | Private company limited by shares | Live |
| OPENWAY ASIA LIMITED | Private company limited by shares | Dissolved |
| OPENWAY INDUSTRIAL LIMITED | Private company limited by shares | Dissolved |
| OPENWAY INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| OPENWAY TRADING LIMITED | Private company limited by shares | Dissolved |
| OPENWEAL LIMITED | Private company limited by shares | Dissolved |
| OpenWell Technology Co., Limited | Private company limited by shares | Live |
| Open-Well Electronic & Technology Co., Limited | Private company limited by shares | Live |
| OPENWIDE INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| OPENWIN INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| Openwines Limited | Private company limited by shares | Live |
| OPENWISE INDUSTRIAL LIMITED | Private company limited by shares | Live |
| Openwit Limited | | Live |
| Openworked Limited | | Live |
| OPENWORLD LIMITED | Private company limited by shares | Dissolved |
| Openx Limited | | Live |
| OpenXMR Limited | Private company limited by shares | Live |
| OPENZIMA COMPANY LIMITED | Private company limited by shares | Live |