The 30-year-old has spent the majority of the past decade with the Swans, having joined the Welsh outfit initially on loan from West Ham United.
Britton, who has made over 400 appearances for the side, is delighted to have extended his stay at the Liberty Stadium until 2016.
"I know I've said it before, but I would love nothing more than to finish my career here," he told the club's official website. "It's been my life for the last 10 years, apart from a six-month sabbatical at Sheffield United, of course, and there's no other place I'd rather be playing my football.
"I never expected things to turn out the way they have when I returned from Sheffield two years ago. The club was in the Championship at the time and there was certainly no guarantee of promotion.
"But we went straight up into the Premier League, have established ourselves in our second season and we are now looking forward to our first major cup final."
Swansea face Bradford City in the Capital One Cup final later this month.