| O.C.T. Imaging Company Limited | Private company limited by shares | Live |
| OCTA COMPANY LIMITED | Private company limited by shares | Dissolved |
| OCTAD INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| OCTAD NETWORK LIMITED | Private company limited by shares | Live |
| OCTAGAIN LIMITED | Private company limited by shares | Dissolved |
| OCTAGEN LIMITED | Private company limited by shares | Live |
| OCTAGON COMPANY LIMITED | Private company limited by shares | Live |
| Octagon Limited | Private company limited by shares | Live |
| OCTAGON CAPITAL LIMITED | Private company limited by shares | Live |
| OCTAGON ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| Octagon Enterprises Limited | Private company limited by shares | Live |
| OCTAGON ENTERTAINMENT LIMITED | Private company limited by shares | Live |
| Octagon Strategy Limited | Private company limited by shares | Live |
| Octagonal gravity Limited | | Live |
| OctagonLab Limited | | Live |
| OCTAGORA LIMITED | Private company limited by shares | Dissolved |
| BALLET OCTAHEDRON LIMITED | Private company limited by shares | Live |
| OCTAL LIMITED | Private company limited by shares | Dissolved |
| Octal Capital Limited | Private company limited by shares | Live |
| OCTAL ENGINEERING EQUIPMENT LIMITED | Private company limited by shares | Live |
| Octal Capital Holding Limited | Private company limited by shares | Live |
| Octal Holdings Limited | Private company limited by shares | Live |
| Octal International Limited | | Live |
| OCTAL KEERUN CO., LIMITED | Private company limited by shares | Live |
| Octal Capital Asset Management Limited | Private company limited by shares | Live |
| OCTAL TV NOVABASE LIMITED | Private company limited by shares | Live |
| Octal Securities Limited | Private company limited by shares | Live |
| Octal Services Limited | Private company limited by shares | Live |
| OCTAL WELLNESS LIMITED | | Live |
| OCTALAND HOLDINGS (HONG KONG) LIMITED | Private company limited by shares | Dissolved |
| OCTALINK LIMITED | Private company limited by shares | Dissolved |
| OCTALINK LIMITED | Private company limited by shares | Live |
| Octalix Asia Limited | Private company limited by shares | Dissolved |
| OCTAM INTERNATIONAL LIMITED | Private company limited by shares | Live |
| OCTAN ENERGY LIMITED | Private company limited by shares | Live |
| OCTANE LIMITED | Private company limited by shares | Live |
| 168 Octane Limited | Private company limited by shares | Live |
| US Octane Fitness Limited | Private company limited by shares | Live |
| OCTANEGAMES (HONG KONG) LIMITED | Private company limited by shares | Dissolved |
| OCTANIUS (HK) LIMITED | Private company limited by shares | Live |
| OCTANS LIMITED | Private company limited by shares | Live |
| OCTANS CORPORATION HONG KONG LIMITED | Private company limited by shares | Live |
| Octans Dorne Limited | | Live |
| OCTANS INDUSTRIAL CO., LIMITED | Private company limited by shares | Live |
| OCTANS INTERNATIONAL LIMITED | Private company limited by shares | Live |
| OCTANS INVESTMENT LIMITED | Private company limited by shares | Dissolved |
| Octant Limited | Private company limited by shares | Live |
| OCTAPALS LIMITED | Private company limited by shares | Dissolved |
| OCTAPLAS LIMITED | Private company limited by shares | Dissolved |
| OCTAPOINTS LIMITED | Private company limited by shares | Live |
| OCTAR COMPANY LIMITED | Private company limited by shares | Dissolved |
| OCTASIC ASIA LIMITED | Private company limited by shares | Live |
| OCTASOURCE LIMITED | Private company limited by shares | Dissolved |
| OCTAVE LIMITED | Private company limited by shares | Live |
| OCTAVE CAPITAL LIMITED | Private company limited by shares | Live Ceased dormancy on 20-Apr-2015 |
| OCTAVEST LIMITED | Private company limited by shares | Dissolved |
| HONGKONG OCTAVEZONE HAIR PRODUCTS CO., LIMITED | Private company limited by shares | Live |
| OCTAVIA PVT LIMITED | Private company limited by shares | Live |
| Octavia Co., Limited | Private company limited by shares | Live |
| OCTAVIA ELECTRICAL APPLIANCES CO. LIMITED | Private company limited by shares | Live |
| OCTAVIA ELECTRONICS LIMITED | Private company limited by shares | Live |
| Octavia events Limited | | Live |
| OCTAVIA INDUSTRIAL LIMITED | Private company limited by shares | Dissolved |
| HK OCTAVIA INDUSTRIAL CO., LIMITED | Private company limited by shares | Dissolved |
| OCTAVIA TRADING LIMITED | Private company limited by shares | Dissolved |
| OCTAVIA TRADING LIMITED | | Live |
| OCTAVIAN LIMITED | | Live |
| Octavian International Limited | Private company limited by shares | Dissolved |
| OCTAVIAN SOCIETY LIMITED -THE- | Company limited by guarantee | Live |
| Octaviana Limited | Private company limited by shares | Live |
| OCTAVIANUS HK LIMITED | Private company limited by shares | Live |
| OCTAVIO LIMITED | Private company limited by shares | Dissolved |
| ITALY OCTAVIUS HONGKONG INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| Octavius Trading Limited | Private company limited by shares | Live |
| Octavo Limited | Private company limited by shares | Live |
| OCTAVO ASIA LIMITED | Private company limited by shares | Live |
| OCTAZENSE LIMITED | Private company limited by shares | Dissolved |
| GERMANY MUNICH OCTBEER LIMITED | Private company limited by shares | Dissolved |
| OCTEK LIMITED | Private company limited by shares | Dissolved |
| OCTEK TECHNOLOGY LIMITED | Private company limited by shares | Dissolved |
| OCTEL NETWORKS LIMITED | Private company limited by shares | Live |
| Octenation Limited | Private company limited by shares | Live |
| OCTER GROUP LIMITED | Private company limited by shares | Live |
| M OCTET LIMITED | Private company limited by shares | Live Commenced dormancy on 27-Jan-2016 |
| OCTEX LIMITED | Private company limited by shares | Dissolved |
| OCTEX HOLDINGS LIMITED | Private company limited by shares | Live |
| OCTEX PROPERTY AGENCY LIMITED | Private company limited by shares | Live |
| OCTEX SPORTSWEARS LIMITED | Private company limited by shares | Dissolved |
| OCTF CO. LIMITED | Private company limited by shares | Live |
| OctFavour Company Limited | Private company limited by shares | Live |
| OCTICORN LIMITED | Private company limited by shares | Live |
| OCTILLION BONANZA LIMITED | Private company limited by shares | Dissolved |
| OCTILLION BONANZA (HOLDING) LIMITED | Private company limited by shares | Dissolved |
| OCTILLION FINANCE LIMITED | Private company limited by shares | Dissolved |
| Octillion Hong Kong Limited | Private company limited by shares | Live |
| OCTIN LIMITED | Private company limited by shares | Dissolved |
| OCTION LIMITED | Private company limited by shares | Live |
| OCTIPAL IP LIMITED | Private company limited by shares | Live |
| HONG KONG OCTIT INDUSTRY CO., LIMITED | Private company limited by shares | Dissolved |
| OCTIUS COMPANY LIMITED | Private company limited by shares | Live |