The 29-year-old has been linked with a move to Arsenal this summer, following some superb performances for the Welsh side.
Williams’ contract had one year left to run, but the centre-back has put pen to paper on a new deal that will keep him at the Liberty Stadium until the summer of 2018.
“I’m delighted to sign a new contract at Swansea City,” Williams said. “I’ve enjoyed fantastic success at this club and I want to keep helping Swansea City progress.
