Anita Louise Combe will play Roxie Hart in Chicago from March 18 to April 28.
From April 29 Denise Van Outen will return to the role in which she scored a personal triumph first time round.
Other cast changes are: Anna Jane Casey returns as Velma Kelly from March 18 to June 1; Sue Kelvin returns as Mama Morton from March 18 to June 1.
Chicago continues to be one of the West End's most popular musicals, and for all the attractions of individual performers it is the show itself that is now the star.
