The actress – who has played Frankie Baldwin for the past two years – will be on screens until the end of the year, though her character will not be killed off.
"The decision to leave Coronation Street has been really difficult as it is the best job I have ever had," she explained to the News of the World. "I had only originally planned to stay for two years, but I didn't anticipate how much I'd fall in love with playing Frankie."
Stephenson has decided to move south with her family, however.
"Our son Max is due to start school next year and my husband James and I had to discuss the future. We felt the time was right for us to move to give Max the time to settle in."
She added: "I'm keen to do other projects and excited about the future but I think the public has not seen the last of Frankie."