| OPHIR CO., LIMITED | Private company limited by shares | Live |
| OPHIR INVESTMENT CO., LIMITED | Private company limited by shares | Dissolved |
| Ophir Jewelry Co., Limited | Private company limited by shares | Live |
| OPHIR TRADE CO., LIMITED | Private company limited by shares | Live |
| OPHIR ENTERPRISE COMPANY LIMITED | Private company limited by shares | Dissolved |
| Ophira Limited | Private company limited by shares | Live |
| Ophis Consulting Limited | Private company limited by shares | Live |
| OPHOL LIMITED | Private company limited by shares | Live |
| OPHONE CO., LIMITED | Private company limited by shares | Live |
| Ophsurin Co., Limited | Private company limited by shares | Live |
| ASIA PEDIATRIC OPHTHALMOLOGIST ASSOCIATION LIMITED | Company limited by guarantee | Live |
| Zhonghua Ophthalmologist League Limited | Private company limited by shares | Live |
| COLLEGE OF OPHTHALMOLOGISTS OF HONG KONG -THE- | Company limited by guarantee | Live |
| Central Ophthalmology Limited | Private company limited by shares | Live |
| HK SHIJIE OPHTHALMOLOGY INVESTMENT MANAGEMENT LIMITED | Private company limited by shares | Live |
| ONE OPHTHALMOLOGY & OPTOMETRY CENTRE LIMITED -THE- | Private company limited by shares | Live |
| ASSOCIATED OPHTHALMOLOGY PRACTICE LIMITED | Private company limited by shares | Live Commenced dormancy on 13-Feb-2015 |
| Premier Ophthalmology Clinic Limited | Private company limited by shares | Live |
| View Ophthalmology Limited | | Live |
| FRANCE OPHY COSMETICS CO., LIMITED | Private company limited by shares | Live |
| O.P.I. LIMITED | Private company limited by shares | Dissolved |
| Opia Limited | | Live |
| OPIC LIMITED | Private company limited by shares | Live |
| OPICORE TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| OPIE COMPANY LIMITED | Private company limited by shares | Dissolved |
| OPIE DIAODING (CHINA) LIMITED | Private company limited by shares | Live |
| Opielok Asia (HK) Limited | Private company limited by shares | Live |
| OPIELOK SHIPPING COMPANY (HK) LIMITED -THE- | Private company limited by shares | Dissolved |
| OPIFICIO INTERNATIONAL CO., LIMITED | Private company limited by shares | Dissolved |
| OPIFICIO MODA LIMITED | Private company limited by shares | Live |
| Opihap Limited | | Live |
| Opiko Training & Counseling Network Limited | Private company limited by shares | Live |
| Hong Kong Opin Selection Trading Limited | Private company limited by shares | Live |
| Opine Limited | Private company limited by shares | Live |
| Chinese Public Opinion News Agency Limited | Private company limited by shares | Live |
| OPINION PUBLISHERS ( ASIA ) LIMITED | Private company limited by shares | Dissolved |
| Candid O'Pinion Limited | Private company limited by shares | Live |
| TA KUNG PUBLIC OPINION MONITORING CENTRE COMPANY LIMITED | Private company limited by shares | Live |
| PUBLIC OPINION REPRESENTATIVES CENTRE LIMITED | Private company limited by shares | Dissolved |
| Opinion Kiss Co., Limited | Private company limited by shares | Live |
| OPINION CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| PUBLIC OPINION CONSULTATION CENTRE LIMITED | Private company limited by shares | Dissolved |
| RICH OPINION TRADING DEVELOP LIMITED | Private company limited by shares | Live |
| OPINION ENTERPRISES COMPANY LIMITED | Private company limited by shares | Live |
| FAVOUR OPINION LIMITED | Private company limited by shares | Dissolved |
| A GENTLEMAN'S OPINION LIMITED | Private company limited by shares | Live |
| GOOD OPINION LIMITED | Private company limited by shares | Live |
| Opinion Prive (HK) Limited | Private company limited by shares | Live |
| Hong Kong People Opinion Company Limited | | Live |
| HONG KONG PUBLIC OPINION LIMITED | Private company limited by shares | Live |
| HONG KONG PUBLIC OPINION RESEARCH LIMITED | Private company limited by shares | Live |
| Opinion International Limited | | Live |
| OPINION NETWORK LIMITED | Private company limited by shares | Live |
| SECOND OPINION LIMITED | Private company limited by shares | Dissolved |
| SECOND OPINION LIMITED | Private company limited by shares | Dissolved |
| Star Opinion Leader Company Limited | Private company limited by shares | Live |
| Third Opinion Limited | | Live |
| United Opinion Sea Products International Limited | | Live |
| Opinionfact Research Limited | | Live |
| Opinionsbridge Marketing Research Co., Limited | Private company limited by shares | Live |
| OPIS LIMITED | Private company limited by shares | Dissolved |
| Opis Investments Limited | Private company limited by shares | Live |
| NEW OPITION LIMITED | Private company limited by shares | Live |
| OPITO LIMITED | Private company limited by shares | Dissolved |
| Opius Limited | Private company limited by shares | Live |
| Opize Limited | Private company limited by shares | Dissolved |
| SPAIN OPKING CHEM INDUSTRY GROUP LIMITED | Private company limited by shares | Dissolved |
| OPKO LIMITED | Private company limited by shares | Live |
| OPLA HK LIMITED | Private company limited by shares | Live |
| HK O-PLANNING COMPANY LIMITED | Private company limited by shares | Dissolved |
| HK OPLAOYCHE FASHION HOLDING LIMITED | Private company limited by shares | Live |
| OPLEX LIMITED | Private company limited by shares | Dissolved |
| HK OPLID (INTERNATIONAL) FASHION LIMITED | Private company limited by shares | Live |
| Oplink HK I Limited | Private company limited by shares | Live |
| Oplink HK II Limited | Private company limited by shares | Live |
| OPLINO INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| OPLUS LIMITED | Private company limited by shares | Live |
| O-PLUS DESIGN LIMITED | Private company limited by shares | Dissolved |
| Oplus Global Limited | Private company limited by shares | Live |
| Oplus Group Limited | Private company limited by shares | Live |
| Oplus Holding Limited | Private company limited by shares | Dissolved |
| Oplus Solutions Hong Kong Limited | | Live |
| OPLUS LIGHTING COMPANY LIMITED | Private company limited by shares | Live |
| Oplus Technology Limited | Private company limited by shares | Live |
| OPLUS TRADING COMPANY LIMITED | Private company limited by shares | Live |
| Oplus2 Creative Limited | Private company limited by shares | Live |
| OPLUSHK CO., LIMITED | Private company limited by shares | Live |
| OPLUSO HK LIMITED | Private company limited by shares | Live |
| OPLUX COMPANY LIMITED | Private company limited by shares | Live Commenced dormancy on 17-Nov-2015 |
| OPLUX (HK) COMPANY LIMITED | Private company limited by shares | Live |
| O.P.M. Consulting Limited | Private company limited by shares | Live |
| O.P.M. HOLDING LIMITED | Private company limited by shares | Live |
| OpmeRithm Limited | | Live |
| OPMMT (Hong Kong) Limited | Private company limited by shares | Dissolved |
| OPNEW Technology Co., Limited | Private company limited by shares | Live |
| OPNPOLE ELECTRIC GROUP COMPANY LIMITED | Private company limited by shares | Live |
| OPO' SPACE LIMITED | Private company limited by shares | Live |
| OPODO HK LIMITED | Private company limited by shares | Dissolved |
| HongKong Dongshan Precision Union Opoelectronic Co., Limited | Private company limited by shares | Live |
| OPOER (HK) HOME GROUP CO., LIMITED | Private company limited by shares | Live |