He was seen in the teen slasher film Demons Never Die, playing Ricky, and appeared in the BBC Two comedy Episodes, alongside Matt LeBlanc and Stephen Mangan.

In 2012, Anderson was cast for the third season of HBO's television series Game of Thrones as Grey Worm, the leader of Daenerys Targaryen's Unsullied army.

[10] In August 2021, Anderson was cast as Louis de Pointe du Lac in the AMC television series Interview with the Vampire.

[11] In his 2024 end-of-year performance review for Vanity Fair, Daniel Canfield praised Anderson’s ability to fully embrace "the majestic emotional range required", in his portrayal.

[12] Anderson’s "incredible performance" during the show’s second season was highlighted by Ro Rusak of Nerdist in their Best TV and Film Moments of 2024.

In 2013, Anderson signed to Columbia Records, and released a free three-track EP, The Middle Child, under the stage name Raleigh Ritchie.

Anderson's musical influences include Erykah Badu, David Bowie, Jill Scott, The Smiths, and Stevie Wonder.

[14] In March 2014, his track "Stronger Than Ever" from Black and Blue was remixed by UK garage producer MJ Cole and released as a standalone single.

"Stronger Than Ever" has been used in television adverts promoting the launch of ITV Encore, as well as in montage videos during Sky Sports' coverage of Professional Darts Corporation events.