She starred in the film Fever Pitch in 1997 which was followed by supporting roles in television series EastEnders, Casualty, Home Fires and Penny Dreadful.

[2][3] Ruth Katrin Gemmell was born in Bristol and grew up in County Durham, first in Barnard Castle before moving to Darlington with her mother upon her parents' divorce.

She played the recurring character of Detective Constable Kerry Cox in the first series of the BBC police procedural Silent Witness, which premiered in 1996.

[11] In November 2011, Gemmell played Lady Shonagon in the adaptation for BBC Radio 4 Woman's Hour of The Pillow Book, by Robert Forrest.

[14] From 1997 to 2025, Gemmell was married in Westminster, London, in 1997 to 2005 to the actor Ray Stevenson, whom she met in 1995 during the filming of TV drama Band of Gold.