In addition, it has also been announced that Sophie Evans, a runner-up on the reality show Over the Rainbow, will assume the role of Dorothy on February 7, succeeding Danielle Hope, who will also play her final performance on February 5.
Grant is perhaps best known from his work on television, most recently on BBC's Strictly Come Dancing. As previously announced, he will also be appearing in the forthcoming Children of Eden benefit concert at the Prince of Wales Theatre on January 29.
Grant will join a company that also includes Edward Baker-Duly as Tin Man, Martin Callaghan as Lion, Paul Keating as Scarecrow, Emily Tierney as Glinda and Marianne Benedict as the Wicked Witch of the West.
Jeremy Sams has directed the production which has choreography by Arlene Phillips. The show features both music from the 1939 film and new songs by Andrew Lloyd Webber and Tim Rice.