Leila Mimmack was born in November 1993 in Leamington Spa to Maddy Kerr and Peter Mimmack who run the Heartbreak Productions theatre company in Spencer Yard, Leamington. Mimmack went to Stratford-upon-Avon College. Her first success as an actress came in 2008 when she won the "Best Teenage Actress" Award at the "Growing Talent Convention" in Paris, beating 300 competitors.
Her first television appearance was in 2010 when she appeared in the BBC series Doctors as Vanessa Finch.
In 2009 she played the werewolf Christa in the Being Human spin off Becoming Human. Furthermore she could be seen in the mini series Mayday, and the television series Inside Men. In 2014 she played a main role in the movie The Sleeping Room.