The 36-year-old Republic of Ireland international, who joined Everton from Sligo Rovers in 2009, said the opportunity to help guide the club through this historic transition played a central role in his decision to stay on.
"Thanks to the hard work of many people, we've been able to get into our magnificent new stadium and pave the way for a brighter future under ambitious new owners - which I want to be part of," Coleman said in a statement released Friday.
The veteran full-back, who holds the club record for Premier League appearances (369), remains a pivotal figure both on and off the pitch. He sits 12th on Everton's all-time appearance list with 428 matches in all competitions - just five behind club legends Dixie Dean and Leon Osman.
Coleman's new deal comes just days before his previous contract was set to expire. Though he suffered a thigh injury during Everton's final match at Goodison Park last month, he is expected to be fit in time for the new campaign.
His longevity and leadership continue to be valued by manager David Moyes, who returned to the club in January and steered the Toffees to a 13th-place Premier League finish.
"In David Moyes, we have the perfect manager to lead us into a new era," Coleman said. "He showed his abilities once again with the way he had us playing after returning last season. As the man who brought me to Everton, I can't speak highly enough of him. He gets this football club."
Moyes echoed the sentiment, emphasizing Coleman's importance as a cultural cornerstone of the dressing room.
"This could be a period of real change at the Club and I want somebody who can help deliver the messages of what it means to be an Everton footballer," said Moyes. "Seamus has always done that, and I know he will continue to do so as we move into a new era."
Everton kick off their 2025-26 Premier League campaign away to Leeds United on August 18.