Poots first appeared on-screen in an episode of Casualty and had a non-speaking role in V for Vendetta, but she was largely unknown when, at the age of 17, Juan Carlos Fresnadillo cast her in the horror film 28 Weeks Later. Since then, she has appeared in films such as Cracks, Centurion, and as the female lead in the 2011 remake of Fright Night alongside Anton Yelchin. Although Poots has never formally trained as an actress, according to Giles Hattersley, she developed her acting skills through a practical apprenticeship that may have served her well, as she is “compellingly natural” in front of the camera.
In 2011, she was chosen by fashion house Chloé to appear in a campaign for its eponymous fragrance shot by Inez van Lamsweerde and Vinoodh Matadin. In 2012, she was selected to star in a Sofia Coppola-directed advertising campaign for a collaboration between fashion label Marni and high street retailer H&M.