The actress left the BBC1 soap in 2013, after arriving in a shock Christmas twist the year before.
Kierston has shared her excitement ahead of returning to our screens, teasing details of her character’s arrival.
“I would describe Ashley as a control freak - I don't believe she has a nice bone in her body but I'm enjoying every minute of playing her,” she tells Digital Spy. "I'm also thoroughly enjoying working with Greg Wood, Jorgie Porter and Charlie Wernham among others.
“Their characters are just a few who get manipulated by Ashley in some way or another, so stay tuned to see if she gets what she wants."
Kierston will make her first appearance on ‘Hollyoaks’ in September, when her character pays a visit to her old friend Trevor - who is nervous about the meeting, and let’s be honest, if Greg Wood’s character is nervous, Ashley must be trouble...