As rumoured, the actress's character Janeece Bryant will bow out in the show's next series, which begins in the autumn.
Healey will appear in a substantial number of episodes in series eight before her departure. Although Janeece will not be killed off, show bosses have promised an "emotional" send-off for the school secretary.
Speaking of her exit, Healey commented: "Waterloo Road and playing Janeece has been a part of my life for six years and I'll be sad to leave the show.
"Working with the cast and crew has been the best time of my life. I'll miss it so much, but I can promise fans my exit will be unmissable - but my lips are sealed!"
Waterloo Road's executive producer Cameron Roach added: "Chelsee's journey with Waterloo Road comes to an end this autumn as we say farewell to Janeece Bryant.
"It's been an incredible experience watching Janeece grow from being a pupil to the school secretary, and we're currently shooting an emotional and engaging departure storyline which we're extremely excited about."
Waterloo Road's new series will be set in Scotland following the show's move from Rochdale.