[1][2] Liddiard moved to Toronto when she was 18,[1] and worked as a part-time office manager there for some time.

[2] In February 2016 Liddiard portrayed the lead character Thai in the Tarragon Theatre production of Kat Sandler's play Mustard.

[2] She achieved wider recognition after being cast in the role of Constable Adelaide Stratton[5] in the British-Canadian-American period mystery series Houdini & Doyle in 2016.

[1][6] From 2017 to 2021, Liddiard played the regular role of Mary, a morality police officer in 1920s Toronto, in the CBC mystery-drama series, Frankie Drake Mysteries.

[7] In 2019, she played airplane crash survivor Madelyn in the first season of the British-Canadian thriller television series Departure.