The 33-year old defender, who had 12 months remaining on his current deal, has officially confirmed new terms that have him remain at Vitality Stadium until 2020.
Francis has made 286 appearances for the Cherries since joining the club from Charlton Athletic in November 2011, initially on loan yet playing a key role in their rise to the top flight from League One.
"I'm delighted to sign a new deal and am really looking forward to the next two years," explained Francis to the club's website.
"The most important thing was to retain our Premier League status for another year and then once that was achieved it was a chance to sit down and discuss things.
"It all happened fairly quickly because negotiations don't take to long when a player wants to stay at the club.
"The club have been great with me ever since I arrived. I feel I've performed to my best over the past seven years and feel very proud to be part of such a successful squad."
Chief executive of AFC Bournemouth Neill Blake commented to the club's website: "Simon is an integral part of the club, both on and off the pitch.
"He was proven himself more than capable of making the step up each time we have gained promotion, and this contract extension is fully deserved.
"As well as being an excellent player, Simon is also an outstanding professional and leader in the dressing room.
"He sets a fantastic example to those around him and that is especially important for the younger players at the club."