A woman was killed after she was run over while lying on the Stuart Hwy in Alice Springs, NT Police has said.

Detective Acting Senior Sergeant Jeshua Kelly said the 21-year-old woman was struck by the vehicle around 3:40am, between Percy Crt and Karnte Rd.

He said St John Ambulance declared the woman dead at the scene while the driver remained at the scene until police arrived.

Anyone who saw the woman between Percy Crt and Karnte Rd prior to the crash can call police on 131 444.