A fuel injector for a compression ignition internal combustion engine which comprises a fuel injection valve having an injection valve member which is moveable in use, under the influence of fuel pressure within an injection valve member control chamber acting upon it, between a closed position and an open position. The fuel injector further comprises a high pressure fuel supply passage to the injection valve member control chamber, and an actuator operable to open and close a discharge valve connected between the injection valve member control chamber and a fuel outlet passage to a low pressure reservoir or drain. A shut-off valve is provided in the high pressure fuel supply passage and the shut-off valve has a shut-off valve member which is moveable in use, under the influence of fuel pressure within a shut-off valve member control chamber acting upon it, between a closed position and an open position. The shut-off valve member control chamber is connectable to the low pressure reservoir or drain via the discharge valve, and a fuel transfer passage is provided between the injection valve member control chamber and the low pressure reservoir or drain.