Police were called to a single-vehicle crash in Old Brighton Rd, in Fairfield, about 1.25pm, a police spokeswoman said.
An extraction was carried out to remove the person from the vehicle, a Fire and Emergency New Zealand spokeswoman said.
A Hato Hone St John spokesperson said one ambulance attended the scene and transported the patient to Dunedin Hospital in a serious condition.
Traffic management was put in place at the time.
Fire crews from Lookout Point, Mosgiel and Roslyn attended.