| JOHNSTON LIMITED | Private company limited by shares | Live |
| ANDERSON JOHNSTON YANG LIMITED | Private company limited by shares | Dissolved |
| ALLAN JOHNSTON & ASSOCIATES LIMITED | Private company limited by shares | Dissolved |
| Johnston Clinic Limited | Private company limited by shares | Live |
| JOHNSTON CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| JM Johnston Consulting Limited | Private company limited by shares | Live |
| JOHNSTON CORPORATION LIMITED | Private company limited by shares | Live |
| JOHNSTON DEVELOPMENTS LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON ENGINEERING CO. LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON ENGINEERING LIMITED | Private company limited by shares | Live |
| JOHNSTON ENTERPRISES LIMITED | Private company limited by shares | Dissolved |
| EVERETT AND JOHNSTON ENTERPRISE LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON FOODS LIMITED | | Live |
| JOHNSTON INTERNATIONAL LIMITED | Private company limited by shares | Live |
| JOHNSTON INVESTMENTS LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON INVESTMENTS LIMITED | Private company limited by shares | Live |
| Jerrice Marcell Johnston Limited | Private company limited by shares | Live |
| JOHNSTON HO LYONS LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON GARMENT MANUFACTURER LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON PROPERTIES LIMITED | Private company limited by shares | Live |
| JOHNSTON PROPERTY CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| Noel and Ruth Johnston Limited | | Live |
| SAMAR JOHNSTON LIMITED | Private company limited by shares | Live |
| Ship & Johnston Limited | Private company limited by shares | Live |
| JOHNSTON TECHNOLOGY LIMITED | Private company limited by shares | Dissolved |
| JOHNSTON TECHNOLOGY LIMITED | Private company limited by shares | Live |
| Johnston Business Technology Limited | Private company limited by shares | Live |
| JPC JOHNSTON TRAINING CONSULTANTS LIMITED | Private company limited by shares | Dissolved |
| WILLIAMS & JOHNSTON LIMITED | Private company limited by shares | Dissolved |
| JOHNSTONE LIMITED | Private company limited by shares | Dissolved |
| JOHNSTONS FAR EAST LIMITED | Private company limited by shares | Dissolved |