The 8-year-old boy collided with a car shortly before noon Sunday in the 700 block of North Peninsula Drive.
Joseph Raico was riding his bicycle south on the sidewalk on Peninsula Drive near his home as Monique Francine Kane of Port Orange was driving north, according to a police report.
The boy struck the right front fender of Kane's car and became unconscious after hitting his head on the roadway.
EVAC ambulance took the boy to Halifax Medical Center, said EVAC ambulance spokesman Mark O'Keefe.
A police report said the boy suffered serious injuries. He was still in surgery Sunday night, according to a nursing supervisor.