The collision happened just after 11:30 p.m. Monday night at the intersection of Western Avenue and 47th Street, according to the Los Angeles Police Department.
Authorities say a white Kia was speeding when it crossed into southbound lanes and hit a black Nissan.
The driver of the Kia died, as well as the 6-month-old baby inside the other car.
A 20-year-old man and 25-year-old woman in the Nissan were taken to the hospital with serious injuries.
The cause of the crash is under investigation. It's unclear if drugs or alcohol were involved.