The 32-year-old actress, who plays catty Janine Butcher on the show, hinted that the soap's poor ratings may have affected her decision.
"I decided a while ago it was time for me to leave Janine behind," Charlie told The Mirror.
The soap star added that she was disappointed to be leaving at this time, as new executive producer Dominic Treadwell-Collins joins.
"When I found out he [Dominic] was returning I was gutted," said Charlie. "I know how fantastic he is and that he will be putting the show back to its rightful place."
The actress, who first quit the show in 2004 and then again in 2012, also hinted that she may return as her character will not be killed off.
"Janine still has a way to go yet and is never far from Walford," said Charlie. "It may be more see you later than goodbye."
Charlie will bid farewell to Janine in 2014, but not before her character plays out a complex murder plot involving ex-love Michael Moon.
The small screen star, who won I'm A Celebrity Get Me Out Of Here last year, will be appearing on Ant and Dec's spin-off, I'm A Celebrity... Get Me Out Of Here! Now! and also plans to explore other roles.