Mafham's professional journey began at the esteemed Bristol Old Vic Theatre School, where he honed his craft before embarking on a four-year tenure with the illustrious Royal Shakespeare Company. During his time at the company, he had the privilege of working alongside renowned directors such as Peter Hall, Danny Boyle, Roger Michell, and Max Stafford-Clark.
On the small screen, Mafham's impressive repertoire includes the role of Mortimer Lightwood in the BBC's critically acclaimed adaptation of Charles Dickens' 'Our Mutual Friend'. He also brought to life the complex and emotionally scarred character of Nigel Hawthorn's son in the multi-award-winning drama 'The Fragile Heart'. Additionally, he portrayed the enigmatic and captivating Simon Kingdom, the errant brother of Stephen Fry's character, in the popular ITV series 'Kingdom'. Furthermore, he played the ruthless and womanizing Dan Woodhouse in the multi-award-winning prime-time series 'The Clinic'.
Mafham's filmography boasts leading roles in notable productions, including Universal Pictures' 'Dragonheart 3' alongside Ben Kingsley, the Norwegian film 'The Heart of Lightness' based on Ibsen's 'Lady from the Sea', and Sony Pictures' 'Sniper 5, Legacy' with Tom Berenger.