Scarlett began her acting career in 2008, portraying Chloe Daniels in an episode of the British TV drama Doctors. In 2009 Byrne earned the role of Pansy Parkinson in the sixth film in the popular Harry Potter series, Harry Potter and the Half-Blood Prince, and she later reprised her role in the final two films of the series. Her latest role was as Brittany in Lake Placid: The Final Chapter, though she has also appeared in several short videos written by fellow Harry Potter star Jessie Cave for her website www.pindippy.com. Her next film will be the action-thriller film Skybound, alongside Gavin Stenhouse.