Film and television
Raison's first film role in 2000 was playing Marianne Faithfull in Suzy Q alongside Carice Van Houten
In 2004, Raison was cast as 'Heather' in Match Point, the first Woody Allen film to be made in London.
In 2005, she appeared in Deuce Bigalow: European Gigolo, which she said "may as well have been the most brutal Lars von Trier film. Another actress and I actually spent a whole night just crying." She called the experience "regrettable from start to finish" and a "hideous, hideous moment and a great lapse of judgement on my part".
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). She requested that the production company let her go in 2009 as she felt that her character could not develop further and wanted to follow up on theatre opportunities.
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.
In 2009, she was featured in the show Plus One. She was originally featured in the Comedy Showcase pilot in 2007, where she wore a fat suit.
In 2010, after leaving Spooks, she played a model called Abbey in the ITV1 comedy-drama Married Single Other.
She had a small role in My Week with Marilyn. She expressed pleasure in being able to work with great British talent and her fascination with Marilyn Monroe.
In 2012, she played DI Georgina Dixon in the second series of Vexed, screened on BBC2.
In 2013, she played 'Harriet Hammond' in the third series of the BBC legal drama Silk; her character was a practice manager who shook up the firm and a potential love interest for her former Spooks co-star Rupert Penry-Jones' character.
In 2014, she had a small role in I Am Soldier, playing "Stella", the lead interrogator in the "Tactical Questioning" portion of the lead character's training.
In July 2014, she was announced as a new cast member of Spotless, a (10 × 1 hour episode) drama produced by Canal+.
In 2018, Raison reprised her role as 'Sylvie' in 6 episodes of Dark Heart, played xenobiologist 'Tessia' in 6 episodes of Nightflyers and appeared in Artemis Fowl.
In May 2019, it was announced that Raison would be joining the main cast of Warrior for the second season.
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.
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.
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.