She is known for her roles in the British sitcoms The Brittas Empire (1991–1997) and Absolutely Fabulous (1992–2012), and has also starred in the West End musicals Cabaret (2006), Wicked (2008) and Mamma Mia!

[5] She appeared in the 1990s British television sitcom The Brittas Empire, playing Carole Parkinson, the receptionist who was prone to depression and fits of emotion who permanently kept her children with her in drawers under her desk, and would sometimes be seen feeding them or washing their clothes.

Along with working extensively with Dawn French and Jennifer Saunders, she has appeared in BBC2's Alexei Sayle's Stuff, A Bit of Fry & Laurie; BBC's Casualty, Material Girl and ITV's The Bill, Midsomer Murders and the sitcom Me, You and Him.

Thorpe has appeared in numerous films, such as Calendar Girls as the rather patronising and superior head of the Women's Institute; Mike Leigh's Life is Sweet; Greystoke; The Calling; and S.N.U.B.

[7] Prior to this, she played Mrs. Lovett in the national tour of Stephen Sondheim's Sweeney Todd: The Demon Barber of Fleet Street, originated the role of Ida Arnold in the Almeida Theatre's original musical, Brighton Rock, and played the role of Madame Thenardier in the hit musical, Les Misérables.

[10] She returned to the Open Air Theatre, Regent's Park to play the parts of Lottie Childs and Patricia Fodor in Timothy Sheader and Stephen Mear's revival of Crazy For You, for which she was nominated for the 2012 Theatregoers' Choice Awards [1] Thorpe returned to Wicked to play Madame Morrible from Monday 22 April 2013 until Saturday 16 November 2013, in place of Louise Plowright who withdrew from the role due to illness.