The 38-year-old – who plays loudmouth mother-from-hell Cilla Battersby-Brown – informed executive producer Steve Frost of her decision to leave at the end of last year.
The soap's writing team are now in the process of working on a dramatic exit storyline for the character.
Of her decision to call time on her role, Wendi said: "I've had a brilliant four years at Coronation Street. It's been filled with wonderful experiences and great opportunities.
"I feel very privileged to have been given the fantastic character of Cilla and I shall really miss her. I'm looking forward to spending a bit more time with my family and pursuing and working on other projects."
Steve Frost commented: "Wendi is a valued member of the cast and she has made the character of Cilla one of the most colourful and memorable characters in soap history.
"We totally understand her reasons for wanting to leave and are grateful that she has given us so much notice – this means that we can spend time writing an exit storyline which will do her and the character of Cilla justice."
Cilla will return to Weatherfield on Monday (Jan 22) from the trip of a lifetime after announcing to Les and the neighbours that she had duped them all over her claim that she was suffering from skin cancer.
Wendi currently commutes from Hertfordshire to Manchester to play Cilla and is "looking forward to combining new roles with spending more time with husband Kenny and daughter Gracie."
Cilla's final scenes on the cobbles are to air in the autumn.