Peggy Mitchell is a fictional character from the BBC soap opera EastEnders. Peggy was initially played by Jo Warne when she first appeared in the episode broadcast on 30 April 1991, featuring in 10 episodes. Peggy was reintroduced in 1994, recast to Barbara Windsor, who made her first appearance in the episode broadcast on 7 November 1994. Peggy became a regular character, and Windsor played the role until she was forced to take a long break due to poor health and departed on 23 May 2003. She returned for two episodes broadcast on 16 and 17 September 2004, before rejoining as a regular character on 8 September 2005. Windsor announced in October 2009 that she would be leaving the show and departed on 10 September 2010. Windsor returned to the show for guest appearances on 20 September 2013, 25 September 2014, 17 February 2015 and 15 January 2016. She then appeared in six episodes between 9 and 17 May 2016, where the character was killed off. Her voice is last heard in the following episode, on 19 May 2016. Peggy's funeral aired on 4 July 2016. An archived recording of her voice was heard on 25 January 2022. On 26 July 2022, it was announced that Peggy would feature in a flashback episode set in 1979, alongside her husband Eric and their children Phil, Grant and Sam. Jaime Winstone played the role of Peggy for this special episode, which aired on 5 September 2022.

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.