She is best known for her roles as Slytherin student Pansy Parkinson in the Harry Potter series,[3][4][5][6] and as Nora Hildegard in The Vampire Diaries.

Byrne began her acting career in 2005 in the short film CryBaby,[5] before portraying Chloe Daniels in an episode of the British TV drama Doctors.

[10] Byrne became a regular cast member for the fourth season of the sci-fi show Falling Skies.

[17] In 2017, Byrne played the role of Lisa in the action-thriller film Skybound, alongside Gavin Stenhouse.

[20] In 2019, Byrne portrayed Bronwyn, a witch in Morgan le Fey’s coven in Marvel’s Runaways.