| ONYX LIMITED | Private company limited by shares | Live |
| ONYX IDS LIMITED | | Live |
| ONYX ASIA LIMITED | Private company limited by shares | Live |
| Onyx Diamonds Asia Limited | Private company limited by shares | Live |
| ONYX CAPITAL LIMITED | Private company limited by shares | Live |
| ONYX CAPITAL LIMITED | Private company limited by shares | Live |
| ONYX CONTAINERS LIMITED | | Live |
| ONYX DIMENSIONS LIMITED | Private company limited by shares | Dissolved |
| Onyx Enterprise Limited | Private company limited by shares | Live |
| ONYX ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| GREEN ONYX LIMITED | Private company limited by shares | Live |
| ONYX HealthCare Limited | Private company limited by shares | Live |
| ONYX INCORPORATED LIMITED | Private company limited by shares | Live |
| ONYX INVESTMENT LIMITED | Private company limited by shares | Live |
| QUALITY ONYX LIMITED | Private company limited by shares | Live |
| SILVER ONYX LIMITED | Private company limited by shares | Dissolved |
| Onyx Solutions Limited | Private company limited by shares | Live |
| Onyx Systems Limited | Private company limited by shares | Live |
| Onyxcina Limited | Private company limited by shares | Live |
| ONYX-FURUKAWA INDUSTRIES LIMITED | Private company limited by shares | Dissolved |
| Onyxslate Limited | | Live |