Taking over from Emma Corrin, who swept awards season in 2020 for their portrayal of the young Diana, Debicki will take Diana through her divorce from Prince Charles (played by Dominic West), her attempts at new relationships, before her death in August 1997.
But while Debicki is a striking lookalike to the Peoples' Princess, where else would we know her from? And what does the actress even think of the weight of taking on such a beloved real-life person?
Here's everything you need to know.
Who is Elizabeth Debicki, The Crown's new Princess Diana?
Elizabeth Debicki, born August 24th 1990, was the eldest of three children to ballet dancer parents. Born in Paris, France, she was raised in Melbourne, Australia from the age of five.
Initially following in her parents' footsteps, Debicki pursued a career in dancing as a child, before switching arts and focusing on acting.
By the time she graduated high school, Debicki had earned two perfect scores in Drama and English. She then pursued a drama degree at the Victorian College of the Arts, graduating in 2010.
Making her film debut in 2011's A Few Best Men, she was spotted by acclaimed film director Baz Lurhmann, who flew her out to audition for his 2013 movie, The Great Gatsby.
She got the part and the rest, as they say, is history, with a collection of well-timed career moves setting her as one of Hollywood's brightest rising stars.
What has Elizabeth Debicki been in before The Crown?
The Great Gatsby role of Jordan Baker gave Debicki her first major foothold in Hollywood. She starred alongside Tobey Maguire, Leonardo DiCaprio and Carey Mulligan.
In 2015, she starred in Guy Ritchie's reboot of The Man From U.N.C.L.E opposite Henry Cavill.
But for most, her name really exploded in 2016 when she starred opposite Tom Hiddleston and Hugh Laurie in The Night Manager, based on the John Le Carré book of the same name.
The Night Manager proved to be an international success, and shortly after that she was cast in the Marvel Cinematic Universe, playing golden Sovereign leader Ayesha in Guardians Of The Galaxy: Volume 2.
Debicki will reprise the role in the third instalment of the franchise, due to be released in 2023, after her character created a new being known only as 'Adam'.
By 2020, she was part of the all-star cast of Christopher Nolan's TENET.
Other major roles include The Cloverfield Paradox, The Kettering Incident and Widows, the last of which earned her no less than 13 best supporting actress nominations for her role opposite Viola Davis.
What has Elizabeth Debicki said about being in The Crown?
Before landing the role of Diana, Debicki had actually previously auditioned for a 'small cameo role' in season two of The Crown. While she didn't get that part, she was remembered when the time came for casting the ill-fated princess.
"This was so many years ago that I sort of put it on the shelf," she told Entertainment Weekly. "I didn't put any eggs in the basket — well, maybe there was one egg in the basket.
"Then, years later, it came back around. When Peter [Morgan, showrunner] actually asked me, I didn't have to give it much thought."
She has also tried to placate worries that The Crown will handle the Princess's death in an insensitive way for the sake of dramatisation.
In October 2022, Debicki was pictured in Paris in outfits similar to what Diana wore in her final days. As such, it's expected Diana's death will air as part of the final season six.
"Peter and the entire crew of this job do their utmost to really handle everything with such sensitivity and truth and complexity, as do actors," she said.
Debicki added: "From that very first meeting [with] Peter, I knew that I'd entered into this space where this was taken seriously [in] a deeply caring way. So that's my experience of the show."
How tall is Elizabeth Debicki?
Princess Diana was 5'10" in real life, taller than the average woman, and roughly the same height as King Charles III, but Elizabeth Debicki is an even more statuesque 6'3" in real life.
“I think my height is something … I mean, you’re probably the first journalist who’s not asked me directly about it in question three: How do you feel about being tall? How has it affected your work? And I always find it an odd question,” Debicki said in an interview Vulture in 2018 while discussing her role in Steve McQueen's Widows.
“[McQueen's] got this incredible radar for what’s actually going on, and you can tell him one thing but he knows it’s the other. But I remember one day he pulled me up [when I was] slouching on set, compensating for somebody else’s height, which was a really seminal moment actually. I remember being really struck by it, because I hadn’t realised I was doing it.”
The Crown season five airs 9 November Netflix.
WATCH: 'The Crown' season 5 trailer