| OrthoCentre Limited | Private company limited by shares | Live |
| OrthoCentre Holdings Limited | Private company limited by shares | Live |
| OrthoCentre Tuen Mun Limited | Private company limited by shares | Dissolved |
| The Orthocorp Limited | | Live |
| ORTHO-DEAL COMPANY LIMITED | Private company limited by shares | Dissolved |
| ORTHO-DEAL STRATEGIC INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| PULCHRA ORTHODONTIA LIMITED | Private company limited by shares | Live |
| ORTHODONTIC CENTER LIMITED -THE- | Private company limited by shares | Live |
| COOKIEPLAN ORTHODONTIC CONSULTANCY LIMITED | Private company limited by shares | Live |
| GRACE ORTHODONTIC CENTRE LIMITED | Private company limited by shares | Live |
| KOWLOON ORTHODONTIC CENTRE LIMITED | Private company limited by shares | Live |
| PACIFIC ORTHODONTIC CARE LIMITED | Private company limited by shares | Live |
| CD ORTHODONTICS LIMITED | Private company limited by shares | Live |
| CENTRAL ORTHODONTICS LIMITED | Private company limited by shares | Live |
| INTERNATIONAL ASSOCIATION FOR ORTHODONTICS HONG KONG STUDY CLUB LIMITED | Company limited by guarantee | Dissolved |
| HONG KONG ASSOCIATION OF ALIGNER ORTHODONTICS LIMITED | Private company limited by shares | Live |
| Orthodontics Asia (Hong Kong) Limited | Private company limited by shares | Live |
| PACIFIC ORTHODONTICS LIMITED | Private company limited by shares | Dissolved |
| TaSK Orthodontics Limited | Private company limited by shares | Live |
| Orthodox Limited | Private company limited by shares | Live |
| ORTHODOX BROTHERHOOD OF APOSTLES SAINTS PETER AND PAUL LIMITED -THE- | Company limited by guarantee | Live |
| ORTHOLITE GROUP LIMITED | Private company limited by shares | Live |
| Ortholite YA Group Limited | Private company limited by shares | Live |
| ORTHOMOVE LIMITED | Private company limited by shares | Live |
| Orthopaedia Company Limited | Private company limited by shares | Live |
| DOCTOR SHA ORTHOPAEDIC CENTRE LIMITED | Private company limited by shares | Live |
| GRAND ORTHOPAEDIC CENTRE LIMITED -THE- | Private company limited by shares | Live |
| AF Orthopaedics Limited | Private company limited by shares | Live |
| ER Orthopaedics Limited | Private company limited by shares | Live |
| Bo Ji TCM Orthopaedics Limited | | Live |
| All-Round Orthopaedics Limited | Private company limited by shares | Live |
| Caleb Orthopaedics Limited | Private company limited by shares | Live |
| Hong Kong Cardiovascular & Orthopaedics MRI Centre Limited | Private company limited by shares | Live |
| HK PACIFIC ORTHOPAEDICS & REHABILITATION CENTRE LIMITED | Private company limited by shares | Live |
| Sincerus Orthopaedics and Rehabilitation Centre Limited | Private company limited by shares | Live |
| Veterinary Orthopaedics Limited | Private company limited by shares | Live |
| Dr. Steven Wong Orthopaedics Centre Limited | Private company limited by shares | Live |
| ORTHOPEDIC AND REHABILITATION PRODUCTS (ASIA) LIMITED | Private company limited by shares | Live |
| Ruixin Gufa Osteopathy Orthopedic Research Limited | Private company limited by shares | Live |
| Orchid Orthopedic Solutions HK Company Limited | Private company limited by shares | Live Commenced dormancy on 29-Oct-2014 |
| Orthopedica AP Limited | | Live |
| Bonovo Orthopedics International, Limited | Private company limited by shares | Live |
| INFINITY ORTHOPEDICS COMPANY LIMITED | Private company limited by shares | Live |
| Mehling Orthopedics Limited | Private company limited by shares | Live |
| ASIAN ORTHOPEDICS TECHNOLOGY HK LIMITED | Private company limited by shares | Live |
| Yikang Orthopedics Limited | Private company limited by shares | Live |
| Orthophase Industrial Limited | | Live |
| ORTHO-RELIEF LIMITED | Private company limited by shares | Live |
| ORTHORXPLAN LIMITED | Private company limited by shares | Live |
| OrthoSmart Limited | Private company limited by shares | Live |
| ORTHOSTIM ASIA LIMITED | Private company limited by shares | Live |
| ORTHOTECH HOLDING LIMITED | Private company limited by shares | Live |
| ORTHOTEK LIMITED | Private company limited by shares | Live |
| FOOTIST ORTHOTIC CENTRE LIMITED | Private company limited by shares | Dissolved |
| POLYCARE ORTHOTIC & PROSTHETIC CENTRE LIMITED | Private company limited by shares | Dissolved |
| ORTHOTIC GROUP (ASIA) LIMITED -THE- | Private company limited by shares | Dissolved |
| Smart Orthotic Technology Limited | Private company limited by shares | Live |
| ORTHOTIX INTERNATIONAL LIMITED | Private company limited by shares | Live |
| ORTHOWORKS LIMITED | Private company limited by shares | Live |
| Orthwell Limited | Private company limited by shares | Live |
| ORTIC LIMITED | Private company limited by shares | Dissolved |
| ORTIKGA LIMITED | Private company limited by shares | Live |
| ORTINA LIMITED | Private company limited by shares | Dissolved |
| ORTINA LIMITED | Private company limited by shares | Dissolved |
| ORTISA LIMITED | Private company limited by shares | Dissolved |
| ORTM Capital Management Limited | Private company limited by shares | Live |
| ORTO LIMITED | | Live |
| ORTO INDUSTRIES CO. LIMITED | Private company limited by shares | Live |
| ORTOFON LIMITED | Private company limited by shares | Dissolved |
| ORTOLAN COMPANY LIMITED | Private company limited by shares | Dissolved |
| ORTOLUX LIMITED | Private company limited by shares | Live |
| ORTON LIMITED | Private company limited by shares | Dissolved |
| ORTON COMPANY LIMITED | Private company limited by shares | Dissolved |
| ORTONA COMPANY LIMITED | Private company limited by shares | Dissolved |
| HONGKONG ORT-PAN-CHINA MACHINERY INCORPORATION LIMITED | Private company limited by shares | Live |
| ORTRAK HOLDING COMPANY LIMITED | Private company limited by shares | Dissolved |
| ORTRAK TRADING COMPANY LIMITED | Private company limited by shares | Dissolved |
| ORTRE LIMITED | Private company limited by shares | Live |
| HONGKONG ORTRONICS INDUSTRY LIMITED | Private company limited by shares | Live |
| ORTSMESSE CO., LIMITED | Private company limited by shares | Live |
| EASTERN ORTUNE LIMITED | Private company limited by shares | Dissolved |
| Solis Ortus Limited | Private company limited by shares | Live |
| ORTUS SOLUTIONS LIMITED | Private company limited by shares | Live |
| ORTUS-T CO., LIMITED | Private company limited by shares | Live |
| Oruga Investment Limited | Private company limited by shares | Live |
| ORUIYA INTERNATIONAL CO., LIMITED | Private company limited by shares | Live |
| ORUM LIMITED | Private company limited by shares | Dissolved |
| FRANCE ORUMP JEWELRY LIMITED | Private company limited by shares | Live |
| Orun Design Limited | Private company limited by shares | Live |
| ORUNIVEX LIMITED | Private company limited by shares | Live |
| ORUS COMPANY LIMITED | Private company limited by shares | Dissolved |
| O.R.V. OVATTIFICIO RESINATURA VALPADANA ASIA PACIFIC HOLDING LIMITED | Private company limited by shares | Live |
| ORVANNA LIMITED | Private company limited by shares | Live |
| ORVEC ASIA PACIFIC LIMITED | Private company limited by shares | Dissolved |
| ORVEMA ASIA LIMITED | Private company limited by shares | Live |
| Orveon Global Hong Kong Limited | | Live |
| ORVEST LIMITED | Private company limited by shares | Dissolved |
| ORVIBO LIMITED | Private company limited by shares | Live |
| ORVICOM HOLDINGS LIMITED | Private company limited by shares | Dissolved |
| ORVIETAN LIMITED | Private company limited by shares | Live |