[1] She originated the title role in Howard Brenton's Anne Boleyn at Shakespeare's Globe Theatre[2] and played Hermione in Kenneth Branagh's production of The Winter's Tale.

[11] From 2002–3, she appeared as Ben-Hur's love interest in a minimalist production of the eponymous play at the Battersea Arts Centre.

[17] From October 2012 Raison starred in The River, a new play by Jez Butterworth, at the Royal Court Theatre (Jerwood) alongside Dominic West.

[18] In 2013–14 she played Anne Faulkner in the theatrical version of Strangers on a Train at the Gielgud Theatre, produced by Barbara Broccoli.

[24] Raison's breakthrough role was as Jo Portman (2005–2009) in the BBC One television drama series Spooks (also broadcast under the title MI-5).

[25] In April 2007 she appeared in the Doctor Who episodes "Daleks in Manhattan" and "Evolution of the Daleks" as Tallulah, a show girl whose opening scene involved singing to a musical number, for which Raison's father played the piano background as part of the BBC National Orchestra of Wales.

[34] In September 2021 it was announced that Raison had joined the first series of Sister Boniface Mysteries playing Ruth Penny, a main character across all ten episodes.

[35] Raison reprised her role as 'Nellie Davenport', as part of the main cast of the third season of Warrior which began airing on HBO in July 2023.

[36][37][38] In April 2023 she was cast as Jean Seberg in L'Enchanteur opposite Charles Berling as Romain Gary which was aired on France 2 in 2024.

She also provides additional voices in other Big Finish audio productions, including other Doctor Who stories and The Avengers.

[41] In 2013 she joined the CGI series cast of Thomas & Friends and provides the voice of Millie (UK/US), first introduced in King of the Railway.

[44] While separated from her first husband, Raza Jaffrey, she began a relationship with her Married Single Other co-star Ralf Little in November 2009, which ended in February 2013.