Announced as one of the Wanderers first three signings on day one, Appiah was part of Western Sydney's back-to-back A-League grand final appearances and the triumphant 2014 AFC Champions League campaign.
He was also awarded the club's ACL Player of the Year award.
Wanderers CEO John Tsatsimas said Appiah’s story holds a special place in the club’s history.
“Kwabena is one of the Club’s success stories; signed as a local Western Sydney boy, he is now an accomplished Hyundai A-League player and Asian Champion,” Tsatsimas said.
“It has been a pleasure to watch Kwabena grow as a player and as a person and we wish him nothing but the best for the rest of his career.
“Kwabena will never be forgotten by the fans, staff or teammates and he leaves us with great memories and a lot of smiles.”
Appiah has departed the club with immediate effect.
