| ON'S CONSTRUCTION LIMITED | | Live |
| O.N.S. TRADE & FINANCE (HK) LIMITED | Private company limited by shares | Live |
| O.N.S CORPORATION HONG KONG LIMITED | Private company limited by shares | Live |
| ON'S INDUSTRIAL COMPANY LIMITED | Private company limited by shares | Dissolved |
| O.N.S. INTERNATIONAL LIMITED | Private company limited by shares | Live |
| ONS' SEA PRODUCTS SUPPLIES LIMITED | Private company limited by shares | Dissolved |
| On's Station Creative Design Limited | Private company limited by shares | Live |
| Onsa Asia Holding Limited | Private company limited by shares | Live |
| HK ONSAATDAAN LIMITED | Private company limited by shares | Live |
| ONSAFE LIMITED | Private company limited by shares | Dissolved |
| ONSAFE (CHINA) LIMITED | Private company limited by shares | Dissolved |
| ONSAFE CONTAINER SERVICE LIMITED | Private company limited by shares | Dissolved |
| ONSAFE INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| ONSAFE TRADING LIMITED | Private company limited by shares | Dissolved |
| ONSALA ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| ONSALE PLASTIC FACTORY LIMITED | Private company limited by shares | Dissolved |
| ONSALES COMPANY LIMITED | Private company limited by shares | Live |
| ONSAN LIMITED | Private company limited by shares | Dissolved |
| ONSANE LIMITED | Private company limited by shares | Dissolved |
| ONSANFANTA COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSAN-TOWA COMPANY LIMITED | Private company limited by shares | Dissolved |
| OnSarang Presbyterian Church of Hong Kong Limited | Company limited by guarantee | Live |
| Onsavii Limited | Private company limited by shares | Live |
| ONSBERG LIMITED | Private company limited by shares | Live |
| ON-SCHEME LIMITED | Private company limited by shares | Dissolved |
| Onscreen Company Limited | Private company limited by shares | Live |
| ONSCREENSHOW (HK) LIMITED | Private company limited by shares | Live |
| ONSEE COMPANY LIMITED | Private company limited by shares | Live |
| ONSEIN HOLDING LIMITED | Private company limited by shares | Live |
| ONSEN LIMITED | Private company limited by shares | Live |
| ONSEN CPA LIMITED | Private company limited by shares | Live |
| CAFE ONSEN TAMAGO LIMITED | Private company limited by shares | Live |
| ONSEN INDUSTRY CO., LIMITED | Private company limited by shares | Live |
| ONSEN ELECTRONICS LIMITED | | Live |
| ONSEN GROUP CO LIMITED | | Live |
| ONSEN INDUSTRY GROUP COMPANY LIMITED | Private company limited by shares | Live |
| Onsen Metal Industrial Limited | Private company limited by shares | Live |
| ONSEN TRADING LIMITED | Private company limited by shares | Dissolved |
| ONSENG LIMITED | Private company limited by shares | Live |
| FRANCE ONSENSE HOLDING LIMITED | Private company limited by shares | Live |
| ONSENSE SHIPPING LIMITED | Private company limited by shares | Live |
| ONSET (ASIA) LIMITED | Private company limited by shares | Live |
| ONSET DESIGN DECORATION AND ENGINEERING LIMITED | Private company limited by shares | Dissolved |
| Onset Investment Limited | Private company limited by shares | Live |
| ONSET TRADING COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSHAN MINERAL LIMITED | Private company limited by shares | Live |
| ONSHINE LIMITED | Private company limited by shares | Dissolved |
| ONSHINE LIMITED | Private company limited by shares | Dissolved |
| ONSHINY GROUP LIMITED | Private company limited by shares | Live |
| ONSHIP LIMITED | Private company limited by shares | Dissolved |
| ONSHOP CO., LIMITED | | Live |
| Onshorer Business Limited | Private company limited by shares | Live |
| ONSIA ALUMINIUM WORK'S (H.K.) COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSIA TRADING LIMITED | Private company limited by shares | Dissolved |
| Onsidai Logistics Co., Limited | | Live |
| ONSIDE ASIA LIMITED | Private company limited by shares | Dissolved |
| SHENZHEN ONSIDE TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| Onside Consulting Limited | | Live |
| Onside Partners Limited | Private company limited by shares | Live |
| Onsieve Limited | | Live |
| OnSign TV Limited | Private company limited by shares | Live |
| ONSING CONSULTANT LIMITED | Private company limited by shares | Live |
| OnSing Decoration (Hong Kong) Company Limited | Private company limited by shares | Live |
| ONSING TECHNOLOGY LIMITED | Private company limited by shares | Live |
| ONSINO TECHNOLOGY CO., LIMITED | Private company limited by shares | Live |
| OnSite Digital Limited | Private company limited by shares | Live |
| Onsite Far East Limited | Private company limited by shares | Live Commenced dormancy on 19-May-2015 |
| ON-SITE (HK) CO., LIMITED | Private company limited by shares | Dissolved |
| ONSITE SERVICES LIMITED | Private company limited by shares | Dissolved |
| Global Onsite Services Limited | Private company limited by shares | Live |
| ON-SITE WORLD AUXILIARIES LOGISTICS LIMITED | Private company limited by shares | Live |
| ONSKY LIMITED | Private company limited by shares | Live |
| ONSKY CREATION LIMITED | Private company limited by shares | Live |
| ONSKY ENTERPRISE LIMITED | Private company limited by shares | Live Commenced dormancy on 28-Jul-1999 |
| ONSKY INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| ONSLAND COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSLAND INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| ONSLOW LIMITED | Private company limited by shares | Dissolved |
| ONSLOW GROUP LIMITED | Private company limited by shares | Live |
| ON-SMARK INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| ONSMART COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSMART ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| ONSMOOTH TRADING LIMITED | Private company limited by shares | Dissolved |
| ONSO LIMITED | | Live |
| ONSON LIMITED | Private company limited by shares | Dissolved |
| ONSON LIMITED | Private company limited by shares | Live |
| ONSON ROBOTIC TECHNOLOGY CO., LIMITED | | Live |
| ONSON CONNECT LIMITED | Private company limited by shares | Live |
| ONSON CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| ONSON DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| ONSON DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| ONSON ENGINEERING LIMITED | Private company limited by shares | Dissolved |
| ONSON ENGINEERING COMPANY LIMITED | Private company limited by shares | Dissolved |
| Onson Engineering Limited | Private company limited by shares | Live |
| ONSON FOODS LIMITED | Private company limited by shares | Dissolved |
| ONSON GARMENTS LIMITED | Private company limited by shares | Dissolved |
| ONSON HOLDINGS LIMITED | Private company limited by shares | Live |
| ONSON INDUSTRIES LIMITED | Private company limited by shares | Dissolved |
| ONSON INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| ONSON INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |