Her breakthrough role was Susan Pevensie in the fantasy film series The Chronicles of Narnia (2005–2010), which grossed over $1.5 billion worldwide and earned her a number of awards.

Popplewell attended North London Collegiate School,[4] and was admitted to Oxford University in 2007 where she studied English Language and Literature at Magdalen College.

[2] Popplewell's first major role was in the film The Chronicles of Narnia: The Lion, the Witch and the Wardrobe (2005), where she played Susan Pevensie at the age of 16.

[8] She reprised her role in the sequel, The Chronicles of Narnia: Prince Caspian (2008), in which she acted with William Moseley, Skandar Keynes, Georgie Henley and Ben Barnes.

[11] In 2012, Popplewell played the character Chyler Silva in the live action 5-part mini series Halo 4: Forward Unto Dawn.

[15][16] Writing for Forbes, Simon Thompson praised her return, calling Popplewell a "familiar and welcome face in the cast".