The former Emmerdale actress has signed up to play a full-time character in the Channel 4 soap later this year.
According to SoapSquawk, Porter's character will "cause chaos" for a particular Chester resident.
Producer Bryan Kirkwood said: "Kirsty Leigh-Porter is a terrific signing for Hollyoaks.
"She will join us later on in the year in a very exciting role.
"She is certainly set to mix things up for one of our much-loved characters."
Porter previously played both Zoe Willson in Coronation Street and Roz Fielding in Emmerdale.
She has also had smaller roles in the likes of Doctors, Shameless and Ashes to Ashes.
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