The motorcycle collided with a car at the intersection of Roscoe Boulevard and Fallbrook Avenue shortly after 1 p.m.
Los Angeles police were following the stolen motorcycle when it crashed, according to LAPD. They say it was not a pursuit.
Officials say that the motorcyclist was going at least 100 mph before the crash.
The motorcycle rider died at the scene. They have not yet been identified.
No further details were immediately known. The investigation is ongoing.