Bellevue police spokesman Michael Chiu said the two knew each other and may have been racing when a BMW driven by the 16-year-old crossed into oncoming traffic and struck an oncoming vehicle.
The BMW burst into flames, killing the boy who was driving. Two other people were injured in the crash and were expected to survive.
Police arrested the 18-year-old man who was driving the other speeding car. He is expected to be booked into the King County Jail for investigation of vehicular homicide.
Coal Creek Parkway was closed for several hours while investigators processed the scene and interviewed witnesses.
The name of the boy who was killed has not been released.