Jockey Simone Montgomerie has died after falling from a horse during a race at the Darwin Cup meeting yesterday.

The 26-year-old fell from leader Riahgrand during race six and was trampled by other horses.

Darwin Turf Club chairman Brett Dixon said Montgomerie sustained traumatic injuries.

"She was transported from the racetrack to Royal Darwin Hospital with St John Ambulance, which was immediately on the scene," he said.

Dixon said two doctors worked on Montgomerie, with the help of paramedics, as she was rushed to hospital.

"It's with great regret that we were advised by the family that Simone passed away shortly after arriving at the hospital," Dixon said.

He said Darwin's racing fraternity was in shock and the club, along with racing stewards and riders, decided to abandon the rest of the meeting, including the feature race the Darwin Cup.

Racing stewards have begun an investigation.

"The Darwin Turf Club, along with the entire industry, offer our deepest condolences and sympathies to the family of Ms Montgomerie," Dixon said.

"Can I just add to that, that Simone, as far as the Darwin Turf Club was concerned, she was our family and we're all devastated by the accident."

Montgomerie's death also sparked an outpouring of grief and tributes on social media from many of Australian racing's biggest names.