The victim was walking across Rosecrans Avenue Saturday night between Budlong and Normandie avenues when a car traveling westbound hit her and kept going.
Officers found the woman lying on the street. She was rushed to Harbor-UCLA Medical Center, where she later died.
Police said several people saw the suspect driving erratically just before the hit-and-run.
"There were some witness statements that indicated that he was driving at a high rate of speed prior to the collision and then afterwards also," said Sgt. Nick Pepper of the Gardena Police Department.
The suspect's vehicle was described as a gray, four-door 2000 or 2001 Honda Civic or Accord with tinted windows. There may be damage to the left front of the car, and the driver's door mirror is missing.
Police said there also were two passengers in the vehicle at the time of the hit-and-run.
Anyone with information was asked to contact Gardena police at (310) 217-6183.