They join the previously announced Michael Crawford as the Wizard and Danielle Hope, who won the role of Dorothy by public vote following the BBC series "Over the Rainbow." They are also joined by Hannah Waddingham as the Wicked Witch of the West and Emily Tierney as Glinda.
Baker Duly's previous West End credits include Gone with the Wind, Salad Days and West Side Story.
Ganly has previously played Amos in Chicago in the West End and also appeared in The Full Monty at the Prince of Wales Theatre. He has appeared on Broadway in The Lonesome West, and was last seen on the London stage in The Beauty Queen of Leeane at the Young Vic.
Keating has been twice Olivier-nominated, for playing the title role in the West End transfer of Tommy from Broadway and for starring in the Pet Shop Boys musical Closer to Heaven. Other West End credits include The Full Monty, Little Shop of Horrors and Don Carlos.
Tierney was last seen in the West End in All the Fun of the Fair and has also appeared in Wicked.
Waddingham has been seen in the West End in A Little Night Music, Spamalot (subsequently reprising her performance as the Lady of the Lake on Broadway), Lautrec and The Beautiful Game. She was last seen on the London stage as the Witch in Into the Woods at the Open Air Theatre, Regent's Park.
The Wizard of Oz is directed by Jeremy Sams and choreographed by Arlene Phillips. Music and lyrics are by Harold Arlen and E Y Harburg, with additional music and lyrics by Andrew Lloyd Webber and Tim Rice. Sets and costumes are designed by Robert Jones. It is produced by Andrew Lloyd Webber and Bill Kenwright.
To book tickets, contact the box office on 0844 412 2957 or visit www.wizardofozthemusical.com