The 30-year-old's current deal was set to expire in the 2014-15 season, so the Toffees moved quickly to retain his services for another four years due to his outstanding form this season.
"We are delighted Phil has agreed to commit his long term future here at Goodison Park," chief executive Robert Elstone told Everton's official website. "Phil is a hugely important and influential player, and I, like many Evertonians, look forward to seeing him play in a Blue shirt for many years to come.
"Discussions have been taking place for a short while, and, now they are completed, I would like to thank Phil and his representatives for the professionalism and courtesy shown throughout those negotiations."
Jagielka joined the club in 2007 from Sheffield United in a 4 million pound deal and has established himself as a key player in David Moyes' side.
In his five years at the club he has made 195 appearances and was named as Everton’s player and players’ player of the year in 2009, when he fired the Toffees into the FA Cup final scoring the winning penalty in the semifinal victory over Manchester United. The center back was cruelly forced to miss the final as ruptured his cruciate ligament a week before the game.
His excellent form for Everton has seen him earn 16 England caps so far, and he scored a goal against Italy this past August.