Continuing to work on television, Knight appeared as a series regular on the BBC One crime drama By Any Means (2013), the CBS mystery American Gothic, and The CW comedy-drama Life Sentence (2018), in addition to portraying Merlin on the ABC fantasy Once Upon a Time (2015) and Don Hall / Dove on the DC Universe / HBO Max superhero drama Titans (2018; 2021).
[7] In March 2017, Knight was cast as Wes Charles in The CW series Life Sentence.
[9][10] In 2020, Knight starred opposite Nicolas Cage and Joely Richardson in the sci-fi cosmic horror film Color Out of Space, directed by Richard Stanley.
[11] In 2021, Knight was cast as Officer Chadwick in season 5 of the TNT crime drama Animal Kingdom.
[12] In 2024, Knight showed up in the 4th season of The Boys on Amazon Prime as Colin, Frenchie's love interest.