Born: 19th November 1979 (as Katherine Sinead Kelly)
Episodes Broadcast: 2016

Katherine Kelly was born in Barnsley, South Yorkshire; the child of two Irish parents, she would regularly visit County Kerry, and she also spent considerable time in the United States. She graduated from the Royal Academy of Dramatic Art in 2001. Kelly made her television debut in 2003, with roles in Last Of The Summer Wine, Silent Witness and the telefilm Sons & Lovers. The following year, she joined the Royal Shakespeare Company. In 2006, Kelly won a starring part in the soap opera Coronation Street; other credits around the same time included No Angels and Life On Mars. After leaving Coronation Street in 2012, she quickly moved on to prominent roles in Mr Selfridge and the second season of Happy Valley. Kelly married Ryan Clark in 2013; they would have daughters Orla and Rose, prior to their separation in 2020.

In 2016, Kelly was cast in the pivotal role of Miss Quill, the only adult regular character amidst the teenaged protagonists of the Doctor Who spin-off Class. She later reprised the role in 2018 for the programme's continuation as a series of audio dramas from Big Finish Productions; however, her availability later led to her replacement by Dervla Kirwan. Kelly had gone on to appear in shows like Strike Back, Criminal: UK and Gentleman Jack, and movies such as Official Secrets starring Keira Knightley and Eleventh Doctor Matt Smith. Amongst her credits during the Twenties were Liar, Curl Up & DI and Bloods on television, and Last Train To Christmas at the cinema.