The actress has been nominated for the Evening Standard Theatre Awards for her role as the heroine in Luigi Pirandello's rarely performed tragedy As You Desire Me which opened at the Playhouse Theatre last month.
Scott Thomas, the star of films such as The English Patient, Four Weddings and a Funeral and Gosford Park, made her London stage debut in Chekhov's Three Sisters in 2003 and won rapturous reviews.
She was hailed as the best of the large crop of film stars to appear in the West End in the past few years. In her new role, she plays Lucia, a married Berlin nightclub singer who has lost her memory and is claimed by another man saying that he is her husband.
Jonathan Kent, former head of London's Almeida theatre, who directs the play, said she had "exactly the mystery and allure to carry it off". Critics described the play as "mind-expanding" and Scott Thomas's role as "running a fine line from Berlin cynicism to Italian elegance in a highly desirable theatrical property".
Competition in the best actress category comes from Eva Best in Hedda Gabler - a role that was reportedly offered to Scott Thomas - and Clare Higgins in Death of a Salesman and Harriet Walter in Mary Stuart. The 45-year-old actress, regularly voted one of the world's most beautiful women, was born in Redruth, Cornwall and educated at Cheltenham Ladies College but moved to Paris as an au pair when she was 18. She speaks French so fluently she even had to dub her part in Four Weddings.
She married a French obstetrician, Francois Olivennes, and has three children, Hannah, Joseph and George. They live in a 19th-century country house. She was recently awarded the Legion d'honneur to add to her OBE.
The actress has hinted at a possible return to Britain, saying she often "gets scared when I realise I'm more French than English after spending more of my life in France than in England".
Her success in film came late: she was 37 when she had her best actress nomination for The English Patient which triggered a series of roles in big-budget Hollywood films The Horse Whisperer with Robert Redford and Sydney Pollack's Random Hearts with Harrison Ford.
She said that in English Patient she felt "overrated" and spent the whole time "wishing I was elsewhere". After Random Hearts she became pregnant and told her agent she did not want to work for a year, although it was longer than that. This summer she also made a British comedy, Keeping Mum, with Maggie Smith and Rowan Atkinson and a French one, La Doublure, by Francies Veber.
Sir Derek Jacobi (best actor), the director Mike Leigh (best play) and Sir Cameron Mackintosh's musical Mary Poppins - up against The Big Life and Billy Elliot - are also on the shortlist for the awards, which will be announced on 28 November.
* BEST PLAY
2,000 Years (Mike Leigh); Bloody Sunday (Richard Norton-Taylor); Harvest (Richard Bean); The Home Place (Brian Friel)
* BEST ACTOR
Brian Dennehy (Death Of A Salesman); Derek Jacobi (Don Carlos); Simon Russell Beale (The Philanthropist)
* BEST ACTRESS
Eve Best (Hedda Gabler); Clare Higgins (Death Of A Salesman); Kristin Scott Thomas (As You Desire Me); Harriet Walker (Mary Stuart)
* BEST DIRECTOR
Richard Eyre (Hedda Gabler); Michael Grandage (Don Carlos); Jonathan Kent (As You Desire Me)
* BEST MUSICAL
The Big Life; Billy Elliot; Mary Poppins