Sammy, who has played the role of Katie for 13 years, is said to have told bosses of her plans to leave shortly after filming dramatic scenes for the soap's Christmas storyline.
An Emmerdale rep declined to comment on the reports, but according to The Sun, Sammy now wants to spread her wings and pursue new acting projects.
There's even speculation that Katie could be killed off, with a source telling the newspaper: "The producers haven't decided yet. Emmerdale love a big death because it's great for their ratings."
Currently on the soap, stable manager Katie is preparing to remarry childhood sweetheart Andy Sugden (played by Kelvin Fletcher).
Sammy has been involved in some major storylines on the Yorkshire-based soap, including Katie's fling with Andy's half-brother Robert and getting trapped after falling down a disused mine.
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