The new deal will keep the 27-year-old with the Saints until the summer of 2014.
“I’m absolutely delighted,” he told the club’s official website.
“I’m really pleased to be part of the club for the next three years and I’m genuinely very happy at signing the new deal.
“There’s a massive buzz at the moment from the chairman and the manager, the coaching staff and the playing staff – they’re all doing a fantastic job and I’m really proud to be here.”
Southampton boss Nigel Adkins said: “He was terrific for us last season as well and I’m really pleased to keep him here and so many others as well for the long term.”