The new deal will keep the 30-year-old on the south coast until 2019.
Francis has had a massive impact at the Vitality Stadium since joining Bournemouth from Charlton Athletic in 2011.
“It’s an easy decision for me,” Francis told Cherries Player HD.
“I am really settled here and I think everyone knows that at the club.
“The manager and the staff know how much I enjoy it, so for me it was an easy decision as long as the ins and outs of the contract were right.
“Thankfully that has all been sorted out and it couldn’t be more perfect.
“It means a lot to me personally because the majority of the lads in the team have been here since League One.
“I think the gaffer obviously recognises how well the lads have done for him.”