Platt trained at East 15 Acting School, and has appeared in many theatre roles.
In September 2008, Platt appeared in The Merchant of Venice playing the role of Narissa at the Octagon Theatre in Bolton until the run ended in November 2008.
Broadcast on 24 April 2011 (Easter Sunday), Jenny Platt made a brief appearance as Violet in a special edition Coronation Street feature episode which featured Sean Tully (played by Antony Cotton) travelling to London to visit his baby son, Dylan.
On 11 February 2012, Platt appeared in Casualty playing Tracey, a hotel cleaner.
Platt married her former Coronation Street co-star Rupert Hill in 2013.