Actors Tosin Cole and Heshima Thompson have signed up to play troubled Solomon and Asher Levi, a pair of brothers who arrive in Albert Square in need of a place to crash.
Meanwhile, Emaa Hussen has taken on the role of Naz - who has problems of her own and is looking for somewhere where she can escape them.
Amanda Fairbank-Hynes completes the main cast in the part of Stephanie 'Stevie' Dickinson, who finds herself in Albert Square after being abandoned in the middle of Walford.
(From left to right: Naz, Solomon, Asher and Stevie)
As the internet drama returns for its second run, the quartet of new characters all end up under the same roof - and it soon becomes clear that each one has something to hide.
EastEnders' executive producer Bryan Kirkwood commented: "EastEnders: E20 made a real impact the first time round, and this second series is set to do the same. The show is a fantastic platform for young, aspiring writers and actors to set the agenda. The audience are in for a real treat as these four exciting new characters will arrive in Albert Square with a bang."
E20 producer Deborah Sathe added: "I am delighted that E20 is going again and proud of what the writers have achieved. This time around, the E20 writers have created four new faces for the Square and their reaction to Walford life is really exciting. It's got all the ingredients of E20, but is bigger, faster, braver and even more fun."
Former Hollyoaks star Roxanne McKee - who played Louise Summers on the Channel 4 soap - will also appear in some episodes of the online show, portraying Pippa, the rich and sophisticated partner of Stevie's ex.
Additionally, producers have confirmed that Britain's Got Talent stars Flawless and fellow dance act Avant Garde are to make guest appearances on the programme.
E20's new ten-part series will launch on September 7, airing on the official EastEnders website every Tuesday and Thursday for five weeks. A weekly omnibus will also be screened on BBC Three.
> Click here to read more about the new cast and characters