| O.I. Limited | Private company limited by shares | Live |
| OIAPH (H.K.) COSMETIC LIMITED | Private company limited by shares | Dissolved |
| OIBAND COMPANY LIMITED | Private company limited by shares | Dissolved |
| FRANCE OIBILI GROUP INTERNATIONAL CO., LIMITED | Private company limited by shares | Live |
| O.I.C. INC. LIMITED | Private company limited by shares | Dissolved |
| OICHI COMPANY LIMITED | Private company limited by shares | Live |
| O.I.C.PRINTING CO., LIMITED | Private company limited by shares | Live |
| OICQ METAL CO., LIMITED | Private company limited by shares | Live |
| OICVM LIMITED | Private company limited by shares | Live |
| O-idea Limited | Private company limited by shares | Live |
| OIDIRE LIMITED | | Live |
| Oieffur Limited | | Live |
| OIET GENERAL TRADING LIMITED | Private company limited by shares | Live |
| OIHK Limited | Private company limited by shares | Dissolved |
| OIII LIMITED | Private company limited by shares | Live |
| OiKa Network HK Limited | Private company limited by shares | Live |
| OIKA.HK LIMITED | Private company limited by shares | Live |
| OIKA.HK COMPLEX LIMITED | Private company limited by shares | Live |
| OIKAI INDUSTRIAL SHARE CO., LIMITED | Private company limited by shares | Live |
| OIKAI HARDWARE PRODUCTS (HK) CO., LIMITED | Private company limited by shares | Live |
| OIKANOR COMPANY LIMITED | Private company limited by shares | Live |
| Oikaris Limited -The- | Private company limited by shares | Dissolved |
| HONGKONG OIKAY INNOVATION TECH CO., LIMITED | Private company limited by shares | Live |
| OIKAZE LIMITED | Private company limited by shares | Dissolved |
| OIKEC F&B CO. LIMITED | Private company limited by shares | Live |
| OIKESION LIMITED | Private company limited by shares | Live |
| OIKI LIMITED | Private company limited by shares | Dissolved |
| Christian Oiki'a Association Limited | Company limited by guarantee | Live |
| OIKO LIMITED | Private company limited by shares | Live |
| OIKODOMEO MANPOWER RESOURCES COMPANY LIMITED | Private company limited by shares | Live |
| OikoLab Limited | Private company limited by shares | Live |
| OIKOS ADVERTISING COMPANY LIMITED | Private company limited by shares | Dissolved |
| Alpha Oikos Limited | Company limited by guarantee | Live |
| OIKOS ASIA HEALTHCARE LIMITED | Private company limited by shares | Live |
| OIKOS (CHINA) LIMITED | Private company limited by shares | Live |
| OIKOS CO., LIMITED | Private company limited by shares | Live Commenced dormancy on 31-Dec-2013 |
| OIKOS CONSULTING LIMITED | Private company limited by shares | Live |
| HUILI OIKOS COATING (HK) CO., LIMITED | Private company limited by shares | Dissolved |
| OIKOS (HONG KONG) LIMITED | Private company limited by shares | Dissolved |
| OIKOS INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| Oikos Land Company Limited | Private company limited by shares | Live |
| OIKOS TRADING COMPANY LIMITED | Private company limited by shares | Dissolved |
| OIKTOS LIMITED | Company limited by guarantee | Live |
| PT OIL, LIMITED | Private company limited by shares | Live |
| WONG YUEN SHUN (EDIBLE OIL) TRADING COMPANY LIMITED | Private company limited by shares | Live |
| KongHou (essential oil) Limited | Private company limited by shares | Live |
| CHINA OIL. (STOCK) GROUP KUNLUN LUBRICANTS CO., LIMITED | Private company limited by shares | Dissolved |
| MIDDLE EAST GROUP (OIL FIELD SUPPLIES) INTERNATIONAL LIMITED | Private company limited by shares | Dissolved |
| SAN HING (OIL) COMPANY LIMITED | Private company limited by shares | Dissolved |
| SYCOR OIL, LIMITED | Private company limited by shares | Live |
| OiLand Beauty Limited | | Live |
| OILAND DRILLING SERVICE LIMITED | Private company limited by shares | Live |
| OILANGELS LIMITED | Private company limited by shares | Live |
| Oilbook Limited | | Live |
| Oilbrite Limited | Private company limited by shares | Live |
| OILCAN CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| OILCAN CONSULTANTS LIMITED | Private company limited by shares | Live |
| OILCO ASIA PACIFIC LIMITED | Private company limited by shares | Live |
| OILCO SUPPLY LIMITED | Private company limited by shares | Dissolved |
| OILCO TOOLS LIMITED | Private company limited by shares | Dissolved |
| OILDICTION LIMITED | Private company limited by shares | Live |
| OILERS LIMITED | Private company limited by shares | Dissolved |
| KOREA HOLA OILFAT INT'L (H.K) COMPANY LIMITED | Private company limited by shares | Dissolved |
| OILFIELD LIMITED | Private company limited by shares | Dissolved |
| OILFIELD LIMITED | Private company limited by shares | Live |
| DGR OILFIELD LIMITED | Private company limited by shares | Live |
| COMMERCIAL OILFIELD CONSULTANTS (HK) LIMITED | Private company limited by shares | Dissolved |
| INTERPAC OILFIELD LIMITED | Private company limited by shares | Dissolved |
| PACIFIC OILFIELD LIMITED | Private company limited by shares | Dissolved |
| PREMIUM OILFIELD SOLUTIONS LIMITED | Private company limited by shares | Live |
| Poly Oilfield Service Company Limited | Private company limited by shares | Live |
| Lai Fei Te Oilfield Supply and Service Company Limited | Private company limited by shares | Live |
| Oilfield Solutions Limited | Private company limited by shares | Live |
| BetterTec Oilfield Solutions Limited | Private company limited by shares | Dissolved |
| KB OILFIELD SUPPLY COMPANY, LIMITED | Private company limited by shares | Dissolved |
| ABLM OILFIELD EQUIPMENT SUPPLY LIMITED | Private company limited by shares | Live |
| Premium Oilfield Technology Limited | Private company limited by shares | Live |
| Topland Oilfield Machinery Limited | Private company limited by shares | Live |
| TUBULAR OILFIELD SUPPLY CHINA LIMITED | Private company limited by shares | Dissolved |
| KUVER OILFIELDS SUPPLY LIMITED | Private company limited by shares | Live |
| OilfieldSide Limited | Private company limited by shares | Live |
| RAY OILFILED ENGINEERING SERVICE LIMITED | Private company limited by shares | Live Commenced dormancy on 25-Jan-2016 |
| HRLD Oil&Gas Group Limited | Private company limited by shares | Live |
| ROFF OIL&GAS LIMITED | Private company limited by shares | Live |
| Sinoenergy Oil&Gas Limited | Private company limited by shares | Live |
| China Oil&Gas Technology Service Limited | Private company limited by shares | Live |
| ROYAL OIL&GAZ CORPORATION LIMITED | | Live |
| OCEANEMED OIL&GAZ HONG KONG LIMITED | Private company limited by shares | Live |
| Star OilGlobal Limited | | Live |
| SHAOXING LIANG YUN OIL&GRAIN MACHINERY CO., LIMITED | Private company limited by shares | Live |
| OiLi (Asia) Limited | Private company limited by shares | Dissolved |
| OILID LIMITED | Private company limited by shares | Live |
| ITALY OILILOI INT'L FINERY LIMITED | Private company limited by shares | Dissolved |
| OILILY GROUP LIMITED | Private company limited by shares | Live |
| OILIMPEX LIMITED | Private company limited by shares | Live |
| Oilin (Hong Kong) Co., Limited | Private company limited by shares | Live |
| OILINKS DEVELOPMENT LIMITED | Private company limited by shares | Dissolved |
| OILINKS INDUSTRIES LIMITED | Private company limited by shares | Dissolved |
| OILIO INTERNATIONAL CORPORATION LIMITED | | Live |
| OILITEC COMPANY LIMITED | Private company limited by shares | Dissolved |