Duffield made his screen debut in the 2006 drama film Under the Mistletoe. He then went on to play a main role in the Nickelodeon mystery series, House of Anubis.
From 2017–2018, Duffield starred in the main role of Holden Matthews in the sci-fi drama series Beyond, which lasted two seasons.
In August 2019, Duffield was cast in the Netflix slasher film There's Someone Inside Your House. The film was released on October 6, 2021.