His notable TV roles include Richard Grey in The White Queen (2013) and Tommen Baratheon in the HBO fantasy series Game of Thrones (2014–2016).

[2] Soon after leaving Billy Elliot, Chapman was cast on the CBBC sitcom The Revolting World of Stanley Brown in the lead role, alongside fellow future Game of Thrones and Blinded by the Light co-star Nell Williams.

Subsequently, he played the lead role of Matthew in the Eoin Macken's drama Here Are the Young Men, supported by Finn Cole, Anya Taylor-Joy, and Ferdia Walsh-Peelo.

In 2015, it was speculated that Chapman was dating Nell Tiger Free, who played Myrcella Baratheon on Game of Thrones;[3][4][5] they subsequently split up and deleted all social-media posts of a romance.

[5] Chapman is close friends with his Game of Thrones co-star Isaac Hempstead Wright (Bran Stark), whom he met through his involvement with the series.