The Cougars gained promotion to the Championship next season with Grand Final victory over Workington, under the stewardship of Demetriou, who played alongside Korkidas at Belle Vue.
Korkidas, 30, enjoyed two spells at Wakewfield, and has also played for Salford, Castleford and Huddersfield in Super League.
The Greek international said: “Wakefield has been a massive part of my life. I’ve enjoyed some great times here career wise and this is also where I met my wife Terri.
“I really would like to say a massive thank you to everyone at the Wildcats, I’ve enjoyed every minute.”