The collision in Humber St at 10am has left a street closed and a car pinned against a historic building.
"It appears one person is in a serious condition, and the Serious Crash Unit are in attendance," police said in a statement.
One car was hit in the side, leaving it pressed against the columns holding up the station's veranda.
There did not appear to be any significant damage to the structure.
Another parked car was lightly damaged on its rear bumper.
A police officer at the scene said the road would effectively be closed and drivers were encouraged to go around the sit via Ribble and Usk Sts.