Sam confirmed his departure via Twitter this afternoon, explaining that he will leave the BBC One show after just one year in the role.
Sam tweeted: "Thanks for all the love this year guys. Means the world. Decided to bow out. Couldn't have done it without you all, thanks @bbceastenders. And of course, tremendous love to my Carter family. True love."
Student and barman Johnny will bow out from Albert Square in an upcoming storyline but bosses are keeping tight-lipped about what his exit will involve.
Following Sam's announcement, it has now been speculated that Johnny could potentially be Lucy Beale's killer.
Ian Beale's daughter Lucy was sensationally killed off in April, and with her killer still on the loose, the storyline is not set to conclude until February 2015, when the soap marks its 30th anniversary with a special live episode.
Sam was cast as Johnny in October 2013, shortly after soap bosses confirmed that Danny Dyer would be joining EastEnders as new Queen Vic owner Mick Carter.
Viewers have watched Johnny in some major storylines, including his emotional scene with Mick, where he broke down in tears revealing that he is gay. The touching moment was later nominated for Spectacular Scene at the British Soap Awards.
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