Beginning performances Aug. 5, prior to an official opening Aug. 11 for a run through Sept. 11, it will be co-directed by the Open Air's artistic director Timothy Sheader and Liam Steele, with the latter also acting as movement director. It is designed by Soutra Gilmour, with musical supervision and direction by Gareth Valentine, lighting by Jon Clark, orchestrations by Chris Walker and sound design by Mike Walker.

The company will also include Marc Antolin, Valda Aviks, Billy Boyle, Gaye Brown, Sophie Caton, Alice Fearn, Mark Goldthorp, Amy Griffiths, Mark Hadfield, Amy Ellen Richardson, Ben Stott and Gemma Wardle.

Sondheim's musical, originally premiered on Broadway in 1987, was first seen in the West End (in a different production) in 1990. It was last revived in the West End in a production at the Donmar Warehouse in 1998. Russell also appeared in that production as Cinderella; this time she will play the Baker's Wife. Prior to appearing in the Broadway transfer of the Menier Chocolate Factory's Sunday in the Park with George, in which she played Dot/Marie and was Tony-nominated in 2008 for Best Actress in a Musical, she was also seen in the West End in revivals of David Hare's Amy's View (opposite Felicity Kendal) and the original cast of Michael Grandage's West End revival of Guys and Dolls (playing Sister Sarah Brown opposite Ewan McGregor's Sky Masterson). She has also appeared in seasons for the Royal Shakespeare Company and the National Theatre, and has previously appeared at the Open Air Theatre, Regent's Park in the musical The Card and as Hermia in A Midsummer Night's Dream.

Waddingham recently completed a week-long concert engagement at the Menier Chocolate Factory, which was recorded for later CD release, where she previously appeared as Desiree Armfeldt in the Menier's production of A Little Night Music, before subsequently transferring with it to the West End's Garrick Theatre and was Olivier nominated for her performance. She originated the role of the Lady of the Lake in Monty Python's Spamalot in the West End production of the show at the Palace Theatre (for which she was also Olivier-nominated), before taking over in the role in the original Broadway production. Other West End musical credits include Lautrec, The Beautiful Game and Tonight's the Night. Regionally, she has appeared in A Chorus of Disapproval (Theatre Clwyd, Wales), Bad Girls the Musical (West Yorkshire Playhouse, Leeds), Smokey Joe's Café (on tour) and The Likes of Us for Andrew Lloyd Webber's private Sydmonton Festival. TV credits include "My Hero," "William and Mary," "Coupling" and "Footballers' Wives." Film credits include "How to Lose Friends and Alienate People," "The Only Boy for Me" and "Note." Later this year she will be seen in the BBC1 comedy "My Family."

To book tickets, contact the box office at 0844 826 4242, or visit www.openairtheatre.com.