Signed in January 2009 from Sligo Rovers by David Moyes for a fee of 60,000 pounds, Coleman has grown into one of the club's most respected captains and longest-serving players in modern history.
The right-back, a firm fans' favourite, leaves behind a remarkable legacy. He holds Everton's record for the most Premier League appearances with 372 and, if he features in his final home match against Sunderland on Sunday, his total appearances in all competitions will rise to 434 - placing him 10th on the club's all-time list.
Coleman has also captained the side 140 times, becoming a symbol of leadership, consistency and commitment through changing eras at the club.
Speaking to evertonfc.com, he said: "After more than 17 years at this great football club, I've decided this season will be my last as a player here.
"I want to thank the fans for their unbelievable support. You've helped me in more ways than you could imagine. I've always tried my best to put Everton Football Club first and you all mean the world to me."
He added: "Coming over here as a 20-year-old from Sligo Rovers to a reserve team, I was just hoping to impress enough to get on the bench. To think I've gone on to make the most Premier League appearances for Everton and to become captain of this great football club - it was beyond my wildest dreams."
Coleman also confirmed he will take time over the summer before deciding his next step, with Everton offering him a potential coaching role. He could also continue playing elsewhere, including for the Republic of Ireland.
"The Club have been unbelievable with me," he said. "I'm going to take a nice, long holiday and look back on what has been an amazing time as an Everton footballer."
He finished with a final message of pride and belonging: "This will always be my football club."
