London's Air Ambulance (LAA) airlifted the woman to hospital after she had to be cut free from the vehicle in Harvil Road by London Fire Brigade (LFB) on Thursday (February 11).
The injured male was treated on the scene by London Ambulance Service and also hospitalised.
An LAA spokesperson said: "The London’s Air Ambulance advanced trauma team was dispatched via aircraft to a road traffic collision in Harefield at 11am today.
"Two patients were treated on scene before one was taken by air to The Royal London Hospital in Whitechapel and the other was taken by road with the London Ambulance Service to St Mary’s Hospital."
London Ambulance Service (LAS) were called at 10.46am and sent multiple resources and treated the incident as a priority.
An LAS spokesperson said: "We sent multiple resources, including HART, an Incident Response Officer and HEMS (Helicopter Emergency Medical Service).
"A female with leg injuries was taken by HEMS to a nearby trauma centre.
"A male with neck and back injuries was also taken by an ambulance crew to a nearby trauma centre as a priority."
London Fire Brigade confirmed they were called at 10.52am to reports of one motor vehicle in collision with a wall.
The brigade sent three engines and their fire rescue unit and cut the trapped woman free by around 12:08pm.
An LFB spokesperson said: "An injured male was treated on the scene and taken to hospital by LAS.
"A woman was trapped and was released by LFB.
"The duty of care is now with the police.
The Metropolitan Police were still assisting with road closures at 1pm.
Harvil Road was closed at the Skip Lane junction and diversions are in place for the U9 bus service.