The woman had been in the road in the area of Oakland and Rock Avenue when she was struck by a 1999 green Honda Civic at about 6:45 a.m., police said.
She was transported to Regional Medical Center of San Jose, where she was pronounced dead at 8:46 a.m.
About 12 hours earlier, a woman crossing Meridian Avenue was struck and killed by a car, police said.
The crash was reported at about 8:35 p.m. and involved a green late 1990s Acura Legend. The car was driving northbound on Meridian Avenue when it struck the woman, believed to be in her 40s, who was in the road just south of West San Carlos Street, police said.
Fire personnel pronounced the woman dead at 8:43 p.m.
The drivers in both crashes stayed at the scene and cooperated with investigators. Police said there was no indication that either driver was intoxicated but that the pedestrians' sobriety levels are unknown.
Both fatal crashes are under investigation and mark the city's first and second auto-pedestrian fatalities of 2012. This morning's crash is the fourth traffic-related fatality of the year.