Lily James, who went to Tring Park School for the Performing Arts, will perform the title role alongside Cate Blanchett as the evil stepmother and Helena Bonham Carter as the fairy godmother.
The 25-year-old was cherry-picked for Kenneth Branagh’s Cinderella remake having shot to fame as Lady Rose McClare in Downton Abbey.
Lily said: “I am still amazed at the success I have had since leaving Tring Park.
“I credit my time there as really giving me the grounding and acting skills to succeed in the world of entertainment.
They encouraged me to be confident in my abilities, while nurturing my dedication and drive for acting.”
Disney released a trailer for the film last month ahead of its launch in March which shows Lily dancing with Prince Charming – played by Game Of Thrones star Richard Madden.
The school’s principal Stefan Anderson said: “We are delighted with Lily’s success and the range of her work from Downton to Cinderella shows her amazing talent.
“Our aim at Tring Park is to give our students the technical skills and expertise in their chosen area and encourage their passion for their talent.
“It is fantastic to see students, like Lily, doing so well in their careers post-Tring.”
Lily has appeared in the film The Wrath of the Titans and in TV shows such as The Secret Diary of a Call Girl and Just William.
She was also part of the stage production of Playhouse by Martin Crimp at the Richmond Orange Tree theatre and Othello with The Wire actor Dominic West in Sheffield.