| 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 Infinity Limited | | Live |
| 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 |
| ONSON INTERNATIONAL ( H.K. ) LIMITED | Private company limited by shares | Dissolved |
| Onson International Holdings Limited | | Live |
| ONSON INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| Onson Quantum (Asia) Limited | | Live |
| Onson Quantum Solutions Limited | | Live |
| Onson Quantum Technology Limited | | Live |
| ONSON SERVICES LIMITED | Private company limited by shares | Dissolved |
| ONSON TECHNOLOGY LIMITED | Private company limited by shares | Dissolved |
| ONSON TECHNOLOGY COMPANY LIMITED | Private company limited by shares | Live |
| ONSON TRADING LIMITED | Private company limited by shares | Dissolved |
| ONSON TRANSPORTATION COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSON WORKS LIMITED | Private company limited by shares | Live |
| ONSONIC LIMITED | Private company limited by shares | Dissolved |
| ONSOON LIMITED | Private company limited by shares | Dissolved |
| ONSOON LIMITED | Private company limited by shares | Live |
| ONSOUND COMPANY LIMITED | Private company limited by shares | Dissolved |
| Onspace Limited | Private company limited by shares | Live |
| WATARY ONSPAN LIMITED | Private company limited by shares | Dissolved |
| ONSPARK LIMITED | Private company limited by shares | Dissolved |
| OnSpark Limited | | Live |
| OnSpec Consulting Group Limited | Private company limited by shares | Live |
| ONSPEED LIMITED | Private company limited by shares | Dissolved |
| ON-SPILL COMPANY LIMITED | Private company limited by shares | Dissolved |
| OnSpot playground Limited | Private company limited by shares | Live |
| ONSRI IMPORT & EXPORT (HONG KONG) LIMITED | Private company limited by shares | Live |
| ONSTABLE LIMITED | Private company limited by shares | Dissolved |
| ON-STAGE LIMITED | Private company limited by shares | Dissolved |
| Onstage Limited | Private company limited by shares | Live |
| ON-STAGE INVESTMENT LIMITED | Private company limited by shares | Live |
| ONSTAGE INVESTMENTS LIMITED | Private company limited by shares | Live Ceased dormancy on 19-Feb-2010 |
| ON-STAGE.HK LIMITED | Private company limited by shares | Dissolved |
| ONSTANDARD LIMITED | Private company limited by shares | Dissolved |
| ONSTAR COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSTAR (ASIA) LIMITED | Private company limited by shares | Live |
| Onstar (Asia) Limited | Private company limited by shares | Live |
| ONSTAR (CHINA) LIMITED | Private company limited by shares | Dissolved |
| ONSTAR CORPORATION LIMITED | Private company limited by shares | Live |
| ONSTAR ELECTRONICS LIMITED | Private company limited by shares | Dissolved |
| ONSTAR ELECTRONICS CO., LIMITED | Private company limited by shares | Live |
| ONSTAR ELECTRONICS GROUP CO., LIMITED | | Live |
| ONSTAR ENGINEERING LIMITED | Private company limited by shares | Live |
| ONSTAR ENTERPRISES LIMITED | Private company limited by shares | Live |
| ONSTAR ESTATE LIMITED | Private company limited by shares | Dissolved |
| ONSTAR INTERNATIONAL EXPRESS LIMITED | Private company limited by shares | Dissolved |
| ONSTAR GROUP LIMITED | Private company limited by shares | Dissolved |
| OnStar Advisory Group Limited | Private company limited by shares | Live |
| ONSTAR (H.K.) LIMITED | Private company limited by shares | Live |
| ONSTAR GARMENT H.K. LIMITED | Private company limited by shares | Dissolved |
| ONSTAR INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| ONSTAR INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| ONSTAR INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| ONSTAR INVESTMENTS LIMITED | Private company limited by shares | Live |
| ONSTAR (OVERSEAS) LIMITED | Private company limited by shares | Dissolved |
| ONSTAR INTERNATIONAL TECH LIMITED | | Live |
| ONSTAR TECHNOLOGY LIMITED | Private company limited by shares | Live |
| ONSTEP COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONSTEP LIMITED | Private company limited by shares | Dissolved |
| ONSTILL LIMITED | Private company limited by shares | Dissolved |
| ONSTOCK LIMITED | Private company limited by shares | Dissolved |
| ONSTON INVESTMENT LIMITED | Private company limited by shares | Live |
| ONSTRIDE INVESTMENT LIMITED | Private company limited by shares | Live |