1. Chapman is known for his portrayal of the protagonist Billy Elliot in the West End theatre production of Billy Elliot the Musical.
2. He also portrayed the lead role of Stanley Brown in the CBBC sitcom The Revolting World of Stanley Brown, and starred as Tommen Baratheon in the fourth, fifth and sixth seasons of the HBO drama series Game of Thrones.
3. He was then promoted to the role of Billy Elliot, mana dia bermain dari 2009 kepada 2011.
4. Chapman is the second longest-serving cast member of the production, and the longest-serving Billy.