The 27-year-old woman was driving a blue Toyota hatchback when she crashed off Kargotich Road in Mardella in the early hours of this morning.
Major crash investigators said it was not yet clear why the car veered off the road, down an embankment and into a tree.
When fire crews arrived the car was engulfed in flames.
Nothing could be done to save the driver, who was trapped inside.
The straight stretch of road has a 100km/h speed limit.
"Our hearts go out to the family involved – we all need to work together to improve road safety in this state," Transport Minister Rita Saffioti said.
The vehicle was seized by police today as they investigate the crash.
Earlier, around midnight in Tuart Hill there was a three-car smash that left a 38-year-old woman injured.
Two other drivers weren't harmed.
Around 7pm on Friday, a food delivery cyclist was struck by a car on Wellington Street in Perth's CBD.
No one was seriously injured.