The incident happened at 6.55pm on Friday, November 15 on Fishergate Hill.
The woman was hit by a Scania double decker bus which was travelling uphill in a bus lane towards the city at the time.
The pedestrian, a 32 year old woman from Preston, was taken to Royal Preston Hospital with serious injuries but she passed away today (18th November).
Nobody on the bus was injured.
Sgt Phil Baxendale of Lancashire Police’s Tactical Operations Division, said: “Our thoughts are with the woman’s family and friends at this incredibly difficult and tragic time. They are being offered support by specially trained officers.
“Our investigation is ongoing and we would encourage anyone with information to speak to us as soon as possible if they haven’t already.”
If you have any information that could assist our investigation, please call 101 or email [email protected] and quote log number 1309 of 15th November.