Anna Katherine Popplewell (born 16 December 1988) is an English film, television and theatre actress. She is known for her role as Susan Pevensie in The Chronicles of Narnia film series since 2005, as Chyler Silva in Halo 4: Forward Unto Dawn since 2012 and Lady Lola in Reign from 2013–2016.

Popplewell began acting at the age of six, taking classes at the Allsorts Drama School. She began acting professionally in the TV production Frenchman's Creek in 1998. She made her film debut in 1999 in the film Mansfield Park, and followed up with supporting roles in the films The Little Vampire (2000) and Girl with a Pearl Earring (2003), with Scarlett Johansson. In 2001, she appeared as Victoria in the BBC serial Love in a Cold Climate.

Her first major role was in the film The Chronicles of Narnia: The Lion, the Witch and the Wardrobe (2005) where she played Susan Pevensie. She has a phobia of mice, which required a double to do part of her scene at the Stone Table in The Lion, the Witch, and the Wardrobe. She reprised her role in the sequel, The Chronicles of Narnia: Prince Caspian, in which she acted with William Moseley, Skandar Keynes, Georgie Henley and Ben Barnes. The film opened in cinemas 16 May 2008. She also made a cameo appearance in the third Narnia film, The Chronicles of Narnia: The Voyage of the Dawn Treader.

In 2012 she played the character Chyler Silva in the live action 5-part mini series Halo 4: Forward Unto Dawn.

In 2013 Popplewell played Lola, a friend of Mary, Queen of Scots, in Reign. Filming took place in Ireland and Canada. She played the role until 2016.