"Princess Diana's spirit, her words and her actions live in the hearts of so many," Debicki said in a statement. "It is my true privilege and honour to be joining this masterful series, which has had me absolutely hooked from episode one."
Debicki will take over as the Princess of Wales for The Crown's final two seasons, replacing Emma Corrin who will play the role in the show's upcoming fourth season. Debicki's casting comes after the recent announcement that Jonathan Pryce has been set to play Prince Philip in the final two seasons, replacing Tobias Menzies in the role. They'll both join Imelda Staunton as Queen Elizabeth, taking over for Olivia Colman, and Lesley Manville as Princess Margaret, taking over for Helena Bonham Carter.
The series was originally going to conclude with Season 5 until creator Peter Morgan changed his mind, realizing there was more story to tell. "As we started to discuss the storylines for Series 5, it soon became clear that in order to do justice to the richness and complexity of the story, we should go back to the original plan and do six seasons," he said. "To be clear, Series 6 will not bring us any closer to present-day — it will simply enable us to cover the same period in greater detail."
While Netflix still has yet to announce a premiere date for The Crown Season 4, we do know that Season 5 won't premiere until 2022 due to production delays caused by COVID-19.
The Crown is currently streaming on Netflix.