Fire crews and the California Highway Patrol responded to the crash at Manchester Avenue at about 3:30 a.m. When they arrived, they found a motorcyclist who had been struck by a vehicle, authorities said.
The victim died at the scene. Information on the other vehicle involved was not immediately known.
The cause of the crash was under investigation.
The three right lanes of the northbound 110 were shut down for several hours overnight and through the early morning, along with the Manchester Avenue off-ramp. All lanes were reopened at 8 a.m.