A teenage boy has died after crashing his dirt bike into a car on a suburban Perth road.

The 15-year-old crashed into the side of a car on Giverny Gardens about 7:30pm on Wednesday night.

He was rushed to Royal Perth Hospital, but died of his injuries on Thursday.

The 49-year-old driver of the car had to be cut free by emergency services.

The Major Crash squad are investigating, and have asked for anyone who witnessed the crash, or the two vehicles in the lead up to it to contact police.