Emergency services - including two ambulances and a hazardous area response team - were called to the scene, on Halifax Road, at around 2.20pm.
It’s thought the injured woman was a passenger in a Toyota Yaris when it smashed into a traffic island and a lamp post.
A man was also in the car and was taken by ambulance to the LGI.
The car landed on its side and firefighters from Halifax and Rastrick had to cut one casualty out of the vehicle.
Motorists are being warned they will face delays following the incident.
Halifax Road in Ripponden is currently blocked and there is slow traffic in both directions between the Elland Road and Stubbing Lane junction.