Carol's exit storyline is being kept closely under wraps, but Lindsey, 54, will film her final scenes later this year.
Lindsey said: "I have had a fantastic time playing the formidable Carol Jackson - however, although I'll miss everything about EastEnders, I feel the time is right for me to move on.
"I've been involved in so many wonderful stories as Carol and now it's time for me to play some different characters and tell some new ones."
Lindsey has been involved in some of the biggest storylines in the past year, including Carol's romance with his childhood sweetheart David Wicks and her breast cancer ordeal.
This isn't the first time Lindsay has left the soap. She first appeared in Albert Square in 1993 before leaving after four years. She briefly came back in 1999 and then made a full-time comeback in 2010.
Executive Producer, Dominic Treadwell-Collins, said the door will be left open for Carol to make a return to Walford.
"EastEnders has always been so lucky to have an actress of Lindsey's calibre in the company – but we always knew that it wasn't indefinitely," he said. "We were thrilled when Lindsey signed for another year to play Carol's breast cancer story – and Lindsey's nuanced, brave and utterly real performance rightfully won her an award and praise from viewers, charities and women who have been through similar experiences to Carol.
"The door will always be open for Carol's return and we wish Lindsey huge love and luck as she embraces new roles away from Walford."
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