The long-standing Carrigstown resident is leaving the TV drama to concentrate on a career as a budding chick-lit author.
Orlaith, who plays Robin Doyle in the hit series, is following in the footsteps of her former colleague Claudia Carroll, who has forged a successful career in writing. But Orlaith isn't giving up acting altogether, and will be soon seen starring alongside Amy Huberman.
The Dubliner admits the inspiration for her debut novel came from her own life story, but says the lead character is nothing like her.
"I don't want to tempt fate and say too much yet, but I've really enjoyed the experience so far," she told the RTE Guide.
"But once I finish up here for the summer, the real work begins.
"I'm going on a holiday first with my boyfriend, and then I'm staying in France to rewrite the book from start to finish."
And there were a few stumbling blocks with the writing of the book, when Orlaith had to get to grips with a new computer.
"I've never owned a computer until six months ago when I got my laptop!
"I used to freak out when it crashed and would say to my boyfriend: 'I think I've broken the World Wide Web.'"
Orlaith won't be killed off from the Carrigstown soap and says she does intend to return at some point.
-- LORNA NOLAN