Authorities said the accident happened at Monterey Road and Ivy Street, which is about two miles west of the Riverside Station, at 5:30 a.m. The train was bound for Union Station in downtown L.A.
The victim's identity has not been released, and it's not clear yet how the accident happened.
There were some delays for Metrolink passengers, but trains were back in service about two hours later.
City News Service contributed to this report.