A musical adaptation of the 1988 film starring Tom Hanks, Big tells the story of Josh Baskin, a 12-year-old boy who grows up overnight after making a wish on a Zoltar Speaks machine at a carnival. The show follows Josh as he attempts to return to his childhood while coping with his new life as a 30-year-old man.
Jay McGuiness was previously announced for the role of Josh Baskin having played the part during the production's UK premiere in Plymouth in 2016.
Joining McGuiness will be Wendi Peters as Mrs Baskin, Kimberley Walsh as Susan Lawrence and Matthew Kelly as George MacMillan.
Further casting will be announced in due course.
Big will play a limited nine-week engagement at the Dominion Theatre between September 6 and November 2.
Big features music by David Shire, lyrics by Richard Maltby and a book by John Weidman.
The London production is directed and choreographed by Morgan Young with design and costume design by Simon Higlett, associate choreography by Helen Rymer, musical supervision by Stuart Morley, lighting design by Tim Lutkin, video design by Ian Galloway, and sound design by Terry Jardine and Avgoustos Psillas.
The musical first premiered in 1996 on Broadway, where it ran for 193 performances and was nominated for five Tony Awards.