Fielding was born in Poole, England,[4] and grew up in Havant, near Portsmouth, before spending two years boarding at Christ's Hospital school in Sussex, where she developed an interest in acting.
She received an Ian Charleson Award Commendation for her role as Pietra in Ibsen's An Enemy of the People at the Sheffield Crucible in 2010 alongside Antony Sher.
[10] In 2012, she was cast as Kim for the UK run of All New People, a black comedy play written by and starring Zach Braff.
[12] Fielding won the 2014 Ian Charleson Award for her reprised portrayal of Portia in The Merchant of Venice at the Almeida Theatre.
[2][13][3] Michael Grandage, one of the four judges, said of her performance in the production, set in a Las Vegas casino, that she had made the familiar role her own, with a "faultless American accent and a huge intelligence in her acting choices".
She had a recurring role in 2016–2017 in the American sitcom The Great Indoors as Brooke, the ex-girlfriend and current boss of Jack (Joel McHale), who must help him transition from an adventurous reporter to an office worker.