Brown commits his future to Harlequins
Harlequins did not specify the length of Brown's new deal, but said that he had "committed his long-term future to the club".
Brown joined Quins' academy in 2002 and has made 248 appearances for the southwest London outfit.
"I am delighted to sign a new contract with Harlequins," he said.
"I believe we have some exciting times ahead of us with the new guys coming into the club this season and the young talent coming through from the academy.
"I feel we can compete at the highest level and push for silverware. Over the coming years, I will be playing at my peak.
"I feel fit, strong and with the experience I have gained by playing international rugby, it will give me every opportunity to achieve the personal goals I have set for myself to win trophies for Quins, continue to play for England and hopefully be part of the 2017 British and Irish Lions tour [to New Zealand]."
Quins Director of Rugby Conor O'Shea added: "Mike is the epitome of what Harlequins stands for. He has come through our academy and become one of the great fullbacks in the game.
"We are all delighted he wants to commit to his only club for what will be, in all likelihood, the remainder of his career."
By re-signing, the one-club man will have been at Harlequins for well over 15 years when his new contract expires, having joined the Academy set up in 2002.
Since making his senior Harlequins debut in 2005 he is currently the most experienced back within the squad with 248 appearances to his name, and 79 tries.
After representing his country throughout the age grade levels, Brown made his senior England debut during the 2007 tour to South Africa and had three caps to his name by 2008.
Having played an integral role in Harlequins' Challenge Cup and Premiership winning seasons, in 2011 and 2012 respectively, and having previously represented the Saxons, he was called into Stuart Lancaster's squad for England's 2012 tour of South Africa.
Since then, Brown's domestic and international career has rocketed. During the 2013/14 season he was named Six Nations Player of the Tournament, The RPA's England Player of the Year and the Premiership Player of the Year.
Following his participation in World Cup, the fullback can now boast 43 international caps.
