Devereux made her theatrical appearance in The Dreamers of Inishdara at the Jermyn Street Theatre alongside "Rocky Horror Show" star Patricia Quinn. However, she is best known for her role as Lady Elizabeth Fitzgerald in Showtime's historical fiction television series The Tudors. She starred as Kate alongside Ross Noble and Tommy Knight in "Stitches" directed by Conor McMahon which premiered at Film4 Frightfest 2012 in Empire Leiceister Square. She has starred in Comedown, an urban horror-thriller film about a group of South-East London teenagers break into an abandoned tower block to install an aerial for a Pirate Radio Station. It is directed by Menhaj Huda, and starring Adam Deacon, Geoff Bell, Jessica Barden, Sophie Stuckey, Slaine Kelly and Jacob Anderson. The film had its premiere at the Grimmfest 2012 film festival on 4 October.
