The crash happened around 11 p.m. Sunday night on the 118 Freeway west of Montair Drive, according to the California Highway Patrol.
Officers responded to the scene and found the victim, identified as a 60-year-old man, lying next to the roadway.
Witnesses reported seeing a large, dark-colored truck driving away from the scene after allegedly hitting and killing the man.
Additional details about the deadly crash were not available.