| OnMyApps Marketing Limited | Private company limited by shares | Live |
| OnMyGrad Limited | Private company limited by shares | Live |
| ONNA ONNA COLLECTIONS LIMITED | Private company limited by shares | Dissolved |
| ONNA GLOBAL LIMITED | Private company limited by shares | Live |
| Onna International Limited | Private company limited by shares | Live |
| Onnekas Limited | Private company limited by shares | Live |
| ONNES LIMITED | Private company limited by shares | Dissolved |
| OnNet Technology Limited | Private company limited by shares | Dissolved |
| ON-NET SERVICE TECHNOLOGY LIMITED | Private company limited by shares | Live |
| ON-NET TRADER LIMITED | Private company limited by shares | Dissolved |
| ONNEX LIMITED | Private company limited by shares | Live |
| Art Onni Limited | Private company limited by shares | Live |
| Onni Consulting Limited | Private company limited by shares | Live |
| ONNI CONSTRUCTION & ENGINEERING COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONNI INTERNATIONAL LIMITED | Private company limited by shares | Live |
| ONNI BUSINESS INTERNATIONAL LIMITED | Private company limited by shares | Live |
| ONNI CORPORATE SERVICES LIMITED | | Live |
| ONNI TRADE LIMITED | Private company limited by shares | Dissolved |
| ONNIC COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONNIS LIMITED | Private company limited by shares | Dissolved |
| ONNIVAS TRADING LIMITED | Private company limited by shares | Dissolved |
| ONNIX COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONNIX INTERNATIONAL LIMITED | Private company limited by shares | Live |
| ONNLUX Limited | Private company limited by shares | Live |
| ONNOR GARMENTS LIMITED | Private company limited by shares | Dissolved |
| ONNURI LIMITED | Private company limited by shares | Live |
| ONNURI CHURCH.HK LIMITED | Company limited by guarantee | Dissolved |
| ONNY LIMITED | Private company limited by shares | Live |
| ONNY SOLE AGENCY COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONNZO LIMITED | | Live |
| ON-OCEAN LIMITED | Private company limited by shares | Dissolved |
| ONODENT LIMITED | Private company limited by shares | Dissolved |
| ONODREW LIMITED | Private company limited by shares | Dissolved |
| ON.OFF LIMITED | Private company limited by shares | Live |
| ONOGAWA LIMITED | Private company limited by shares | Live |
| ONOK H.K LIMITED | Private company limited by shares | Dissolved |
| ONOKO LIMITED | Private company limited by shares | Live |
| ONOKO INTERNATIONAL LIMITED | Private company limited by shares | Live |
| Onokoon International Fashion Brand Co., Limited | Private company limited by shares | Live |
| ONOMO LIMITED | Private company limited by shares | Dissolved |
| Onon Agency Limited | Private company limited by shares | Live |
| Onon Dining Management Limited | Private company limited by shares | Live |
| OnOn Holding Limited | | Live |
| ONON ONLINE INTERNET (HONG KONG) LIMITED | Private company limited by shares | Live |
| OnOn Shipping Hong Kong Limited | Private company limited by shares | Dissolved |
| ONON hotpotland Limited | Private company limited by shares | Live |
| ONON TECHNOLOGIES COMPANY LIMITED | Private company limited by shares | Dissolved |
| ON&ON TRADING LIMITED | Private company limited by shares | Live |
| HK ON-ON DOOR TRADING GROUP LIMITED | Private company limited by shares | Dissolved |
| ONORATO COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONORD GROUP LIMITED | Private company limited by shares | Dissolved |
| ONORICH LIMITED | Private company limited by shares | Dissolved |
| ONORO LIMITED | Private company limited by shares | Dissolved |
| ONOSOM LIMITED | Private company limited by shares | Live |
| ONOWAY LIMITED | Private company limited by shares | Dissolved |
| ONOWAY LIMITED | Private company limited by shares | Live |
| ONPAC LIMITED | Private company limited by shares | Dissolved |
| ONPAC ENTERPRISES LIMITED | Private company limited by shares | Live |
| ONPAC INTERNATIONAL LIMITED | Private company limited by shares | Live |
| ONPACE LIMITED | Private company limited by shares | Dissolved |
| ONPAK COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONPAK TRADING DEVELOPMENT LIMITED | Private company limited by shares | Live |
| ONPAK ENTERPRISES LIMITED | Private company limited by shares | Live |
| HONG KONG ONPAPER INVESTMENTS LIMITED | Private company limited by shares | Live |
| ONPAR INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| ONPARK COMPANY LIMITED | Private company limited by shares | Live |
| ON-PATH COMPANY LIMITED | Private company limited by shares | Live |
| ONPAY SERVICE CO., LIMITED | | Live |
| ONPEACE LIMITED | Private company limited by shares | Dissolved |
| ONPEARL COMPANY LIMITED | Private company limited by shares | Live |
| ONPEU ENTERPRISES LIMITED | Private company limited by shares | Live |
| ONPEX LIMITED | Private company limited by shares | Dissolved |
| ONPEX Limited | Private company limited by shares | Live |
| ON-PIN ASIA LIMITED | Private company limited by shares | Dissolved |
| ONPITH LIMITED | Private company limited by shares | Dissolved |
| ONPITH DEVELOPMENT LIMITED | Private company limited by shares | Live |
| ONPLAN COMPANY LIMITED | Private company limited by shares | Dissolved |
| ONPLAN LIMITED | Private company limited by shares | Dissolved |
| ONPLAN LIMITED | Private company limited by shares | Dissolved |
| ONPLUS ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| ONPLUS-KIN WIN (JV) ENGINEERING LIMITED | Private company limited by shares | Live |
| ONPOINT LIMITED | Private company limited by shares | Dissolved |
| ONPOINT LIMITED | Private company limited by shares | Live |
| ONPOINT TRADE CO., LIMITED | Private company limited by shares | Live |
| ONPOINT CONSULTING COMPANY LIMITED | Private company limited by shares | Live |
| ONPOINT DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| ONPOINT EVENTS LIMITED | Private company limited by shares | Live |
| ONPOINT (HK) LIMITED | Private company limited by shares | Dissolved |
| ONPOINT TECH. (HK) CO., LIMITED | Private company limited by shares | Live |
| ONPOINT INDUSTRIES LIMITED | Private company limited by shares | Live |
| ON-POINT INDUSTRIES (CHINA) LIMITED | Private company limited by shares | Live |
| ONPOINT INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| HONG KONG ONPOINT INTERNATIONAL TRADING CO LIMITED | | Live |
| Onpoint International Trading Co., Limited | Private company limited by shares | Live |
| OnPoint Management Limited | Private company limited by shares | Live |
| Onpoint Media Limited | | Live |
| OnPoint Business Solutions Limited | Private company limited by shares | Live |
| ONPOINT WORLDWIDE LIMITED | Private company limited by shares | Dissolved |
| ONPOOL INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| ONPOOL TRADING LIMITED | Private company limited by shares | Dissolved |