The captain, who turns 33 in August, has been at Goodison Park since 2007 and was previously committed to the club until 2017.
“It???s always nice to feel wanted,??? he told the club website. “Being rewarded with the extra year gives me that motivation to keep striving to get better and to keep going for as long as possible.
“It wasn???t the longest negotiations ever ??? it only took a couple of minutes rather than hours. I love it here, I want to stay here and thankfully enough the club felt the same.
“The contract was drawn up and I popped back after a little holiday to sign it. Now I look forward to getting back for pre-season.”
Centre-half Jagielka was named Everton’s player of the season last month, and his manager Roberto Martinez said:??”It???s great news that Phil is extending his relationship with the club. He has excelled as a leader and as a captain of our football club for the last two seasons.
“I am sure everyone connected with the club will join me in being absolutely delighted that he has signed this extension to his deal.”