[10] As a model, she worked in campaigns for Armani, Dolce & Gabbana, Burberry and Paul Smith[7] and appeared on the covers of several fashion magazines.

[11] In 1993, Guillory made her screen debut in Riders, a TV adaptation of Jilly Cooper's novel of the same name, for which the casting directors needed a young actress who was able to ride a horse.

Guillory went on to appear in the BBC production Take a Girl Like You, a television adaptation of Kingsley Amis's novel of the same name.

She portrayed Jenny Bunn, the story's virginal heroine, and gained critical attention for her part in the period piece.

[14] In 2001, Guillory continued with other roles in predominantly British films, including Oblivious, Late Night Shopping (with husband Enzo Cilenti), The Last Minute, and Superstition [de].

[15] She played Emma, the fiancée of Pearce's character, who was killed early in the film and whose death set off its main events.

She was impressed by director Penny Woolcock's unconventional style of shooting, without rehearsing the actors, using raw takes and improvisational performances.

In May 2004, Guillory starred in a new stage production of The Shape of Things at the New Ambassadors Theatre in London, with husband Cilenti.

She was cast as Jill Valentine, one of the lead characters in the video game adaptation sequel Resident Evil: Apocalypse.

The film makers had searched widely for an actress to portray the video game character and found her in Guillory, who had to "please not only the movie-going audience but also the gamers."

[18] Guillory studied the original character's movements by watching playthroughs of the video game Resident Evil 3: Nemesis.

[18]After the success of Resident Evil: Apocalypse, Guillory appeared in other film and television roles, including Beauty (2004), Marple: A Murder Is Announced (2005), In the Bathroom (2005), The Virgin Queen (2005), Silence Becomes You (2005), and Rabbit Fever (2006).

[citation needed] In 2006, Guillory was a lead in the ensemble cast of the fantasy Eragon, the film adaptation of the novel by Christopher Paolini; the role reunited her with The Time Machine co-star Jeremy Irons.

Although Arya is a key character in the film, Guillory had little screen time and went on to say jokingly: "I've been trying to explain to friends who've seen the trailer [...] I'm like, "[...] but that's my whole part!

[21] In 2007, she starred in the Spanish production The Heart of the Earth, and later in the year finished filming the horror/thriller Victims and the fantasy novel adaptation Inkheart.

Guillory will play Jessica, the 2008 couple's neighbour, a woman who has Asperger syndrome who went to school with the husband (and father-to-be) and shares a secret with him.

In 2015, she joined the main cast as scientist Natalie Yelburton in the new thriller series Fortitude, commissioned by Sky Atlantic and set in the fictional Arctic oil settlement of the same name.

In January 2016 she also joined the cast of Sky One's new series, Stan Lee's Lucky Man, playing the character Eve.

In 2001, readers of Esquire UK voted Guillory "Britain's Most Eligible Woman" and featured her in a pictorial in the magazine.

In August 2004, Guillory and Cilenti cycled five stages of the Tour de France to raise money for charity.