The pedestrian, a woman in her 50s, has suffered injuries to her legs and has been taken to University Hospital Southampton following the incident at 2.45pm on West Street outside St Faith’s Church.
Two ambulance crews, an ambulance officer and the Hampshire and Isle of Wight Air Ambulance were sent to the scene where two patients were treated.
A spokesman for South Central Ambulance Service said: ‘One patient has already been treated by our crews for serious injuries and has been taken to hospital accompanied by the ambulance and air crew.
‘One other patient was treated on scene by our ambulance crew but they were not taken to hospital.’
A police spokeswoman confirmed officers attended.