Emergency services were called to Denby Dale Road, close to Hampsons Plantworld, shortly after 1.30pm today.
West Yorkshire Fire service said only one car had been involved in the collision.
It said crews from Ossett and Wakefield had worked to free the trapped person, who was then handed into the care of paramedics.
A Yorkshire Ambulance Service spokeswoman said a rapid response vehicle and two ambulances had been sent to the scene along with members of the Hazardous Area Response Team.
She said one patient had been taken to Pinderfields Hospital in Wakefield for further treatment.
Neither service was able to confirm the age or gender of the casualty.