Lorraine, who plays the Dales' Steph Stokes, will bow out at the end of the year in a storyline which ensures closure for the character.
Of her decision to leave, the actress said: "Four years ago Steve Frost, our then producer of Emmerdale, presented me with a complex character. I have enjoyed greatly the challenge he set. I hope Steph's fans will agree, she was an unpredictable and intriguing crazy lady and I loved her but there is only so much a good girl can do!
"I have decided to leave Steph to her fate and re-unite with friends and family and get a life. Thank you Emmerdale and thank you all our lovely viewers."
Series Producer, Kathleen Beedles added: "After four years of fantastic stories we are very sorry that Lorraine will be leaving, but are excited about the terrific storyline that is coming up for her."