The defender, who had come off contract last week, has penned a new 12-month deal.
Keane, 32, told evertonfc.com: “I love Everton and have been massively proud to play for this club since the day I joined so I’m delighted to extend my stay here.
“The manager wants a competitive squad and I still feel I have a lot to give to Everton.
“We’ve been through a difficult few years but it’s an exciting time ahead for us as players and our brilliant fans.
“We’ve got a world-class new stadium to play in, and our form under the manager last season shows there’s a lot of reasons to be positive. I’m looking forward to being part of it.”
Good value to squad
Everton manager David Moyes added: “We are pleased Michael has agreed to stay with us. His performances at Fulham and Newcastle at the end of last season showed the value he can bring to our squad. We will need his experience and professionalism as we go forward."