Lucie Jones and Ashley Roberts will take over the roles of Jenna and Dawn in the West End production of Waitress from 17 June.
Jones, whose credits include Legally Blonde, Rent, The Wedding Singer and We Will Rock You will play the lead part of Jenna when Katharine McPhee leaves the show in June.
Roberts, who reached the final of Strictly Coming Dancing in 2018 and is formerly a member of the Pussycat Dolls, takes over from Laura Baldwin in the show and makes her West End debut in the production.
Waitress opened at the Adelphi Theatre earlier this year, with WhatsOnStage critic Sarah Crompton saying: "Waitress is a treat… it leaves a pleasantly sweet taste in the mouth."
Sara Bareilles' songs feature in the piece, which is based on the 2007 film by Adrienne Shelly and has a book by Jessie Nelson. The show tells of a waitress and avid baker in a small town working in a diner who is stuck in a toxic relationship.
The show is directed by Diane Paulus, with choreography from Lorin Latarro, lighting from Ken Billington and designs from Scott Pask.
Waitress is currently booking until 19 October. Laura Baldwin, who currently plays Dawn, will return to the role at the end of the summer.