Nicola Roberts will make her theatre debut in the West End revival of City of Angels.
The musical will return to London at the Garrick Theatre with previews from March 6, 2020.
Josie Rourke's production returns to the West End after running at the Donmar Warehouse in 2014.
Roberts, who rose to fame as part of girl group Girls Aloud, will appear in the role of Avril/Mallory.
She joins a cast that includes Rosalie Craig as Gabby/Bobbi, Rebecca Trehearn as Donna/Oolie, Hadley Fraser as Stine and Vanessa Williams as Carly/Alaura.
Roberts said: “I am delighted that Josie and the production have chosen me to be Mallory for City of Angels.
"To make my acting debut in this show and to work with such a fantastic company of actors and Josie Rourke is a dream come true for me.”
City of Angels interweaves two plots, one following the writing of a screenplay in the legendary Hollywood of the 40s; the other, the enactment of that screenplay.
It features music by Coleman, lyrics by David Zippel and a book by Larry Gelbart.
Further casting includes Theo James as Stone, Jonathan Slinger as Buddy Fiddler, Marc Elliott as Panchos/Munoz, Nick Cavaliere as Sonny, Adam Fogarty as Big Six, Mark Penfold as Luther Kingsley, Rob Houchen as Jimmy/Dr Mandril and Joshua St Clair as Peter Kingsley.
Cindy Bellot, Sadie-Jean Shirley, Manuel Pacific and Ryan Reid will play the Angel City 4.
City of Angels runs at the Garrick Theatre from 6 March 2020 to September 5 2020.