The 27-year-old, who joined the Cherries in May 2014 from Newcastle United, will remain at the south-coast outfit until at least the summer of 2021.
Devon-born Gosling began his career at Plymouth before moving onto Everton and Newcastle.
The former England U21 international scored four goals in 37 appearances last season as the Cherries comfortably avoided relegation from the Premier League.
“I’ve really enjoyed my three years here,” Gosling told Bournemouth’s website. “It’s gone so fast but I believe I’ve improved immensely, working with the manager and his coaching staff.
“In that time we have gained promotion and spent two years in the Premier League, so it couldn’t have gone any better.
“My goal now is to be a mainstay in the side and keep adding to my game.”
Bournemouth boss Eddie Howe says he is “delighted” to have tied the midfielder down to a long-term deal, after also signing Nathan Ake, Jermain Defoe and Asmir Begovic this summer.
“I am delighted Dan has signed a new contract as he is a very important part of our squad and what we are trying to achieve here,” he said.
“He has great talent, huge energy and offers real quality to our midfield. Despite only being 27, Dan also has plenty of Premier League experience and that is crucial for a team that is still relatively new to the division.”