EastEnders: E20 (sometimes just E20) is a British Internet soap opera, which began airing on 8 January 2010. A spin-off from the established BBC soap EastEnders, it is set in EastEnders' regular setting of Albert Square, a Victorian square in the fictional borough of Walford, in the East End of London. Each series follows a group of teenage characters: Zsa Zsa Carter (Emer Kenny), Leon Small (Sam Attwater), Fatboy (Ricky Norwood) and Mercy Olubunmi (Bunmi Mojekwu) in series 1; Asher Levi (Heshima Thompson) and his brother Sol (Tosin Cole), Naz Mehmet (Emaa Hussen), and Stevie Dickinson (Amanda Fairbank-Hynes) in series 2; and Ava Bourne (Sophie Colquhoun), Donnie Lester (Samuell Benta) and Faith Olubunmi (Modupe Adeyeye) in series 3. The show's title comes from Walford's fictional London postcode district, E20. The four characters from series 1 also appear in EastEnders, as well as Faith from series 3.

EastEnders: E20 originally aired as part of the main show's 25th anniversary celebrations. It was devised in a bid to develop and nurture new talent, including writers, actors, composers and remixers, and target a younger audience, as well as to attempt to drive more people onto the Internet. The series was the idea of executive producers Diederick Santer, who wanted a show where regular EastEnders characters would be in the background, and John Yorke, who wanted to improve the portrayal of teenagers in EastEnders and to get younger people writing for it.

The show's writers, all newcomers aged between 17 and 22, were selected through a writing competition, and created the series at a BBC summer school. The theme tune was also selected through a competition, promoted on BBC Radio 1. The show primarily operates as a standalone series but also cross-references storylines of the main soap, and features cameo appearances from several of the regular characters from EastEnders. The episodes are between three and 16 minutes each in length and are available via EastEnders' official website. Omnibus editions were also available on BBC iPlayer, BBC Red Button and, from April 2010, BBC Three.