Spark studied English literature at Lady Margaret Hall, Oxford, graduating with a First-Class Honours degree in 2004.
[1] In 2008, Spark played schoolteacher Mercy Chant in the BBC adaptation of Thomas Hardy's Tess of the D’Urbervilles.
[5] Spark plays the role of Detective Inspector Kate Gemmill in the 2015 BBC drama The Interceptor.
[7] In 2017, Spark took the lead role in the Theatr Clwyd's production of Skylight, a play by David Hare.
[8] In 2019, she appeared for the Royal Shakespeare Company in Crooked Dances, a new play by Robin French, as the character Katy Porlock.