The child was identified as Ilyas Kurban, of Corona, according to the coroner's office.
Authorities said around 5:36 p.m. Friday, authorities responded to a car crash in the 900 block of Matthews Place.
When paramedics arrived, they found a 3-year-old child had been hit by a vehicle. He was rushed to a hospital, where he died of his injuries.
Based on witness statements, the child was riding his bike when he and a green Mazda SUV crashed.
Authorities said it was unclear if drugs or alcohol were involved in the crash. No arrests had been made.
The investigation is ongoing.