The California Highway Patrol says it happened on Highway 41 south of Jensen Avenue at 1 am.
Officers say an 83-year-old was driving a Hyundai Tucson south on the freeway when the pedestrian went directly in front of the vehicle.
The pedestrian was declared dead at the scene.
Officers say the driver stayed and fully cooperated with the investigation.
Drugs or alcohol were not factors in the crash.
The pedestrian has not been identified.