| OHC Opportunity Investment Limited | | Live |
| Asia Investment Opportunity - HR1 Limited | Private company limited by shares | Live |
| Asia Opportunity Investments Limited | Private company limited by shares | Dissolved |
| Jupiter Opportunity Limited | Private company limited by shares | Live |
| Orient Best Opportunity Limited | Private company limited by shares | Live |
| OPPORTUNITY PACIFIC HK LIMITED | Private company limited by shares | Dissolved |
| Pramerica China Opportunity Company, Limited | Private company limited by shares | Live |
| SOLARWORK OPPORTUNITY ONE LIMITED | Private company limited by shares | Live |
| First Opportunity Solutions Limited | Private company limited by shares | Live |
| United China Opportunity Limited | Private company limited by shares | Live |
| VAST OPPORTUNITY LIMITED | Private company limited by shares | Dissolved |
| Opporty Limited | Private company limited by shares | Live |
| Opposite Limited | Private company limited by shares | Live |
| The Opposites Limited | | Live |
| HONG KONG OPPOSON INTERNATIONAL TRADE CO., LIMITED | Private company limited by shares | Live |
| OPPOSOURCE COMPANY LIMITED | Private company limited by shares | Live |
| Asian Opps I Limited | Private company limited by shares | Live |
| OPPS GROUP LIMITED | Private company limited by shares | Live |
| OPPS! Production Limited | Private company limited by shares | Live |
| OPPTAGON LIMITED | | Live |
| OPPTEL CO., LIMITED | Private company limited by shares | Live |
| OPPTEL ELECTRIC LIMITED | Private company limited by shares | Dissolved |
| OPPTIMUS LIMITED | Private company limited by shares | Dissolved |
| OPPTIMUS II LIMITED | Private company limited by shares | Dissolved |
| OPRA PRIMA LIMITED | Private company limited by shares | Live |
| OPRE LIMITED | Private company limited by shares | Live |
| OPRIDE AUDIO CO., LIMITED | Private company limited by shares | Dissolved |
| O'PRIMA LIMITED | Private company limited by shares | Dissolved |
| O'PRIMA HK LIMITED | Private company limited by shares | Dissolved |
| OPRO ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| OP-ROCK LIMITED | Private company limited by shares | Dissolved |
| O.P.S. LIMITED | Private company limited by shares | Dissolved |
| Ops5 Limited | Private company limited by shares | Dissolved |
| OPSAP LIMITED | Private company limited by shares | Live |
| OpSec Cloud Limited | | Live |
| OPSEN BELL (CHINA) INVESTMENT CO., LIMITED | Private company limited by shares | Live |
| HONGKONG OPSEN (GROUP) LIMITED | Private company limited by shares | Live |
| OPSEN TRADING LIMITED | Private company limited by shares | Live |
| Opshine Technology Company Limited | Private company limited by shares | Live |
| OPSIS TECHNOLOGIES GROUP (HK) LIMITED | Private company limited by shares | Dissolved |
| Opslea Beauty & Spa Limited | Private company limited by shares | Live |
| OpsMasta Limited | Private company limited by shares | Live |
| Opsobjects Limited | Private company limited by shares | Live |
| Opson Company Limited | Private company limited by shares | Live |
| Opson (Hong Kong) International Trading Co., LIMITED | Private company limited by shares | Live |
| OPSON TECHNOLOGY LIMITED | Private company limited by shares | Live |
| OPSREADY LIMITED | Private company limited by shares | Live |
| OPSVIEW (HK) LIMITED | Private company limited by shares | Live |
| OpsVista Systems Limited | Private company limited by shares | Live |
| Opsweet Bakery Company Limited | | Live |
| OpSynergy Limited | | Live |
| 5 O.P.T. LIMITED | Private company limited by shares | Dissolved |
| OPTOMETRY (OPT) CENTRE LIMITED -THE- | Private company limited by shares | Live |
| OPTACE TECHNOLOGIES CO., LIMITED | Private company limited by shares | Live |
| Nanpeng Optact Vision Investment Holdings Co., Limited | | Live |
| Optact Vision Limited | | Live |
| OPTAGON LIMITED | Private company limited by shares | Live |
| OptAim (HK) Limited | Private company limited by shares | Live |
| OPTAKE INDUSTRIAL LIMITED | Private company limited by shares | Live |
| Optal Asia Limited | Private company limited by shares | Live |
| Optamac HK Limited | Private company limited by shares | Live |
| OPTAMAX LIMITED | Private company limited by shares | Live |
| OPTANA LIMITED | Private company limited by shares | Dissolved |
| OPTARE CONSULTANCY LIMITED | Private company limited by shares | Live |
| OPTASIA LIMITED | Private company limited by shares | Live |
| OptAsia Healthcare Limited | Private company limited by shares | Live |
| OPTATIVE COMPANY LIMITED | Private company limited by shares | Live |
| OPTCLA INTERNATIONAL CO., LIMITED | Private company limited by shares | Dissolved |
| OPTCOM TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| OPTCOOL LIMITED | Private company limited by shares | Live |
| OPTCORE TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| OPTDEAL LIMITED | Private company limited by shares | Live |
| OPTDISPLAY TECHNOLOGY (H.K) CO., LIMITED | Private company limited by shares | Live |
| SHENZHEN OPTE ENERGY DEVELOPMENT CO., LIMITED | Private company limited by shares | Live |
| OPTE OPTOELECTRONIC (HONGKONG) CO., LIMITED | Private company limited by shares | Dissolved |
| Optec Co., Limited | Private company limited by shares | Live |
| OPTEC ELECTRONICS LIMITED | Private company limited by shares | Live |
| GIKEN OPTEC (ASIA) LIMITED | Private company limited by shares | Live Commenced dormancy on 21-Sep-2015 |
| GIKEN OPTEC HONG KONG LIMITED | Private company limited by shares | Live |
| OPTEC (HONG KONG) LIMITED | Private company limited by shares | Live |
| KOCENT OPTEC LIMITED | Private company limited by shares | Live |
| OPTEC TECHNOLOGY LIMITED | Private company limited by shares | Live |
| OPTECH LIMITED | Private company limited by shares | Dissolved |
| CHINTEK OPTECH LIMITED | Private company limited by shares | Live |
| Optech Co., Limited | Private company limited by shares | Live |
| OPTECH HEALTHCARE CO., LIMITED | Private company limited by shares | Dissolved |
| OPTECH ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| HK GENGMING OP-TECH COMPANY LIMITED | Private company limited by shares | Live |
| OP-TECH PHOENIX COMPANY LIMITED | Private company limited by shares | Dissolved |
| VARITRONIX OPTECH LIMITED | Private company limited by shares | Dissolved |
| WISE POWER OPTECH COMPANY LIMITED | Private company limited by shares | Live |
| OPTECK INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| OPTECK MANUFACTURING GROUP LIMITED | Private company limited by shares | Live |
| OPTECS LIMITED | | Live |
| OPTEGY LIMITED | Private company limited by shares | Live |
| OPTEK CO., LIMITED | Private company limited by shares | Live |
| ADVANCED OPTEK CO., LIMITED | Private company limited by shares | Live |
| OPTEK ELECTRONICS COMPANY LIMITED | Private company limited by shares | Live |
| Optek Technology Limited | Private company limited by shares | Dissolved |
| OP-TEK TECHNOLOGY LIMITED | Private company limited by shares | Live |