Merseyside Police were called to reports of a collision between a Hyundai car and a scrambler bike at the junction of Belle Vale Road and Lee Vale Road at 19:10 BST on Thursday.
The rider was taken to Aintree University Hospital but was pronounced dead a short time later.
The Hyundai driver was uninjured and assisted with inquiries, police said.
Officers are appealing for witnesses. Belle Vale Road was closed between Beresford Road and Halewood Road for several hours following the crash.
A scrambler bike rider has died after being seriously injured in a crash in Belle Vale, south Liverpool.