The collision happened in Deepdale Road, near Moor Park High School and Sixth Form, at around 8.05am (June 13).
Police closed the road in both directions whilst emergency services attended the scene.
North West Ambulance Service (NWAS) confirmed that the woman, aged in her early 40s, has suffered "major trauma injures".
She has since been taken to the Major Trauma Centre at Royal Preston Hospital.
An NWAS spokesman said: "We were called to Deepdale Road at 8.07am, after reports of a traffic accident.
"A woman in her early 40s has been taken by ambulance to Royal Preston Hospital.
"She has suffered major trauma injuries."
The road closure has led to rush hour congestion in Deepdale Road and surrounding roads, with Skeffington Road reportedly gridlocked.
A police spokesman said: "A call came in at shortly after 8.15am reporting a collision between a car and a female pedestrian in Deepdale Road.
"She has suffered suspected head and leg injuries and has been taken to hospital.
"Road closures are in place."
Buses are being diverted due to the Deepdale Road closure, with delays to the 6 and 19 services expected.
A spokesman for Preston Bus said: "Following a police incident, Deepdale Road is currently closed between St George's Road and Blackpool Road.
"Services 6 and 19 are diverting via St Georges Road, Skeffington and Lowthorpe Roads. Stops on Deepdale Road at Moor Park and PNE are not being served.
"Delays are probable. Apologies for any inconvenience."
More to follow...