The 31-year-old, who played 276 games and won three premierships with the Cats after making his debut in 2000, joins fellow veterans Paul Chapman, Josh Hunt and James Podsiadly in exiting the club.
 
"Football has provided some great opportunities," Corey said on Wednesday morning.
 
"I have been fortunate to have met outstanding people, from players, coaches, staff and trainers that I am proud to call my friends.
 
"The club has always put its people first, and has always been there for me, helping my development and challenging and supporting me as both a player and a person.
 
"There are many people to thank: the supporters that have accepted me as a Geelong person and shared their club with me; my family and friends for their unbelievable support that continues; and to the media that always treated me fairly.
 
"The club is in great shape to continue to be successful. I wish the club, the players and all the people that play a variety of roles behind the scenes all the best in the future years.
 
"It has been a privilege to play for the Geelong Football Club and I will always be grateful to all the people that have made the experience so fulfilling."
 
A quiet and assuming person, who was a fierce competitor on the field, Corey joined Geelong from East Perth in the 1999 NAB AFL Draft.
 
A midfielder whose trademarks were his clearance work and attacking use of handball, he leaves as one of the most decorated players in the Cats' history.
 
Corey won the club's best and fairest, the 'Carji' Greeves Medal, in 2005 and 2008. He was also selected in the All Australian team on two occasions.
 
Over his career, he polled 92 Brownlow Medal votes.
 
A big-game player, Corey averaged 27 disposals in his four grand final appearances and helped the Cats to seven top-four finishes during his career at Simonds Stadium.
 
 "Joel has been the ultimate team-first player, and is one of the league's most respected players for the way he competed and played the game," Cats coach Chris Scott said.
 
"Joel was one of the most critical players in the Geelong teams that claimed the three premierships.
 
"He did a huge amount of contested work in the midfield and was one of the bravest and hardest players in the game.
 
"He could easily have chased personal accolades, but he instead always put the team's needs ahead of anything else.
 
"His teammates loved playing with him and he was a true leader around the club.
 
"Hopefully Joel stays in the game, as he has a lot to offer."