She began acting as a child, and became known for starring as Lucy Pevensie in the fantasy film series The Chronicles of Narnia (2005–2010), which grossed over US$1.5 billion worldwide and won her several accolades.

[2] Henley made her acting debut as Lucy Pevensie in 2005 film The Chronicles of Narnia: The Lion, the Witch and the Wardrobe, based on the C.S.

[5] Since the release of The Lion, the Witch and the Wardrobe, Henley has appeared as Jill in the stage play Babes in the Wood put on by Upstagers' Theatre Group, which ran from 27 January to 4 February 2006.

[8][9] During her time at University of Cambridge Henley studied English and performed on stage in Play It Again, Sam by Woody Allen; The Penelopiad by Margaret Atwood; The Trojan Women; A Clockwork Orange by Anthony Burgess; and in the CUADC/Footlights annual pantomime.

Henley has also directed projects including co-directing Sweeney Todd: The Demon Barber of Fleet Street, and After Seymour (the latter of which she co-wrote).

In 2016, she appeared in the stage productions of: Skylight by David Hare; Girl, Interrupted (an adaptation of the book with the same name; and Swallow by Stef Smith.