Police said they were alerted by St John to reports a car collided with a pedestrian in Man St at 3.05pm today.
A reporter at the scene said St John ambulance staff and members of the public helped the woman lying on the side of the road by the kerb.
St John spokesman Gerard Campbell said the seriously hurt woman is in her 20s. Details of her injuries were not known.
Two ambulances and two police cars attended the scene.