Davis, 24, was one of the first players to sign with the GIANTS in 2011 and one of the club's inaugural captains.
The key defender has won plaudits for his leadership and overcoming a career threatening kidney injury which sidelined him for 10 weeks in 2014. He has played 46 games for the GIANTS for a career total of 64.
His contract extension follows the re-signings of Jon Patton, Adam Tomlinson, Toby Greene, Nick Haynes, Josh Kelly and Adam Kennedy among others.
Davis said he jumped at the opportunity to extend his contract from 2016 to 2018.
“One of the major reasons for my decision to sign on for an extra two years is that this is the place where I think I’m the best chance to win a premiership,” he said.
He said he was encouraged by the players who had already re-committed to the club.
“We have a few boys who aren’t too far away either so it’s an exciting time, the boys are really buying in and we’re excited about where this footy club can go."
Chief Executive David Matthews said the club was delighted to secure Davis on a long-term basis.
"Phil is a leader at this club and has been here from the start. His decision to lock in is a great show of faith in the GIANTS and the direction we're heading in," he said.
"He is a key player in our defence and has won the respect and admiration of everyone for the way he has overcome significant injuries."
Head Coach Leon Cameron said he was delighted to secure Davis.
“It’s a great endorsement of the club to have somebody of Phil’s talent, character and leadership commit to the GIANTS long term,” he said.
The GIANTS will begin their NAB Challenge campaign against the Gold Coast Suns at Blacktown this Saturday, March 7 at 4.10pm. Entry is free for GIANTS members with game access, or tickets are available through Ticketmaster.
