Symonds played 26 Tests and 212 limited-overs internationals for his country.
The news broke overnight, with police confirming an investigation into the accident while former team-mates and opponents including Adam Gilchrist and Michael Vaughan paid tribute.
“Early information indicates, shortly after 11pm the car was being driven on Hervey Range Road, near Alice River Bridge when it left the roadway and rolled.
“Emergency services attempted to revive the 46-year-old driver and sole occupant, egter, he died of his injuries.
“The Forensic Crash Unit is investigating.”
Symonds, affectionately known as “Roy”, played 26 Tests and 212 limited-overs internationals for his country and was noted especially for his ferocious hitting in the middle order.
Former wicketkeeper Gilchrist tweeted crying and heartbreak emojis followed by the simple message: “This really hurts. #roy #rip”
Ex-England captain Vaughan wrote: “Simmo .. This doesn’t feel real .. #SKEUR"