The fire was reported just before 4 a.m. on the 2400 block of Gladys Avenue but the flames were extinguished in less than an hour, according to the Los Angeles County Fire Department.
The person, whose identity has not been released, was found dead inside the garage which appears to have been converted into an apartment.
Arson investigators were on the scene, said L.A. County Dispatch Supervisor Melinda Choi, but a cause has not been determined.
No other injuries were reported.