Roles in the Golden Globe-nominated National Geographic series Genius, BBC One’s Privates, Upstart Crow, NBC's Dracula, ITV’s Mr. Selfridge, Lewis, Midsomer Murders, and Crackle’s Snatch followed.

Having left Leeds University, in 2009 Fox's first professional role was playing Perkin Warbeck, in Channel 4’s TV Mini Series, Henry VIII: Mind of a Tyrant.

At the end of 2011, Fox was then cast in Channel 4’s critically acclaimed Fresh Meat, created by Jessie Armstrong and Sam Bain, in which he demonstrated his comedic touch, playing Ralph, a manipulative counterweight to Jack Whitehall’s JP, in an arc that spanned two seasons.

The film was a roaring success gaining Naji Abu Nowar the Venice Horizon's Award, collecting multiple accolades on the way to two BAFTA wins, and an Oscar Nomination.

The play was a huge success, with The Evening Standard giving it four stars, noting his "comedic timing"[3] Additionally, The Stage commended the production for its "sharp wit and genuine warmth," crediting Fox's role in delivering "a compelling blend of humour and heartache"[4] In 2019 Fox was cast in Sky Atlantic's Riviera (2019), starring opposite Juliet Stevenson, Will Arnett, and Julia Stiles which smashed records for their biggest debut series ever.

He played Nico Eltham, a psychopathic megalomaniac, bringing a "chilling sophistication" to the role that The Telegraph noted for its "mesmerising intensity" with his portrayal being met with widespread acclaim.

[7] He then moved onto Andrew Davies's ITV/Masterpiece (PBS) produced Sanditon (2019-2023),[8] in which he played manipulative and narcissistic Edward Denham, opposite Theo James and Rose Williams, the show was critically acclaimed and spanned three seasons.

The Guardian described his role as "refreshingly honest and layered," stating, "Fox delivers a performance that makes the character's moral ambiguity both compelling and credible,"[12] The success of the show lead to it being nominated for a Royal Television Society award.