Whittaker made her professional debut in The Storm at Shakespeare's Globe in 2005. She has since worked in film, television, radio and theatre. In 2007 she stood in at short notice for an unwell actress in the Royal Court's production of The Seagull, and appeared in a fundraising play at the Almeida Theatre.

Whittaker's radio credits include a 2008 adaptation of Blinded By The Sun by Stephen Poliakoff, which also starred Harriet Walter and Alex Jennings and the role of Lydia Bennett in Unseen Austen an original drama by Judith French.

She appears in the forthcoming film The Kid. In 2009 she will work on the film Ollie Kepler's Expanding Purple World and the BBC 2 drama Royal Wedding.

Whittaker is from the village of Skelmanthorpe in Yorkshire. She trained at the Guildhall School of Music and Drama, graduating in 2005 with the gold medal for acting. She is married to actor Christian Contreras.