Police were called to a single-vehicle crash at Old Brighton Rd, in Fairfield, at about 1.25pm, a police spokeswoman said.
An extrication was performed to remove the person from the vehicle, a Fire and Emergency 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 in place.
Fire crews from Lookout Point, Mosgiel and Roslyn attended.