Mark Fowler is a fictional character in the BBC soap opera EastEnders. Mark, an original regular character when the series started in February 1985, became a semi-regular after his original portrayer David Scarboro was written out of the role in April 1985. Scarboro made brief returns to the role in 1986 and 1987. Scarboro died by suicide in April 1988 and subsequently Mark was recast two years later on his return, with former Grange Hill regular Todd Carty taking on the role. From this point the character was a permanent fixture in the series and Carty remained in the role until the character was written out of the series in early 2003.

EastEnders is a British television soap opera created by Julia Smith and Tony Holland which has been broadcast on BBC One since February 1985. Set in the fictional borough of Walford in the East End of London, the programme follows the stories of local residents and their families as they go about their daily lives. Within eight months of the show's original launch, it had reached the number one spot in BARB's television ratings, and has consistently remained among the top-rated series in Britain. Four EastEnders episodes are listed in the all-time top 10 most-watched programmes in the UK, including the number one spot, when over 30 million watched the 1986 Christmas Day episode. EastEnders has been important in the history of British television drama, tackling many subjects that are considered to be controversial or taboo in British culture, and portraying a social life previously unseen on UK mainstream television.