The Toffees previously announced that Coleman had been offered an extension, with his previous deal set to expire on June 31.
However, the 34-year-old will remain at Goodison Park for at least another year after putting pen to paper on a new contract.
Coleman told the club's official website: "Everyone knows how much Everton means to me which is why it is special to sign this new contract and continue to play for this great club.
"From the moment I joined more than 14 years ago, the support my family and I have had from our fans and everyone around the Club has been amazing and I never take for granted just how fortunate I am to represent Everton. That has included the honour of wearing the captain's armband in recent years.
"I'm keen to continue helping my teammates in any way I can, while passing on my experience to the younger lads and contributing on the pitch as much as possible.
"We know the past couple of seasons have not been good enough for Everton Football Club. But I can assure our fans that I'll continue to give everything to put that right and, under the manager and his staff, our players will know what is expected of them for the season ahead."
Coleman is currently recovering from a medial knee ligament injury he sustained in May's 2-2 draw with Leicester City.
Commenting on Coleman's contract renewal, Everton boss Sean Dyche said: "We are all pleased Seamus has signed his new deal.
"I have hugely enjoyed working with him since becoming Everton manager. He is a top professional who helps to set high standards every day and makes it clear what it means to play for Everton Football Club. His quality and experience continue to be of great use and will do again once he's back fit."
Coleman, who joined Everton from Sligo Rovers for £60,000 in the summer of 2009, is currently the longest-serving active player in the Premier League.
The Republic of Ireland international has made 352 top-flight appearances for the Toffees, and he is just two games away from equalling the club's Premier League appearance record, which is currently held by Tim Howard.
Everton will be relieved to agree a new deal with their club captain following the recent departures of Asmir Begovic, Yerry Mina, Tom Davies and Andros Townsend.