Joining the previously announced Raymond Coulthard as King George VI and Jason Donovan as Lionel Logue are: Nicholas Blane, Jamie Hinde, Felicity Houlbrooke, Claire Lams, Katy Stephens and Martin Turner.
The play, which is adapted from the Oscar-winning movie, has previously toured the UK and run in the West End.
Directed by Birmingham Repertory Theatre's Artistic Director Roxana Silbert, the production opens at the Chichester Festival Theatre on Thursday 5th February 2015. The play tells the iconic story of King George VI's relationship with his speech therapist.
One of the most successful British films of all time, The King's Speech won four Academy Awards, including Best Picture, Best Actor and Best Director, as well as seven BAFTAs, including Best Film.