Wasps have announced that the 21-year-old will remain at the club until at least the summer of 2015.
The news follows confirmation of Launchbury's place in the England matchday 23 to face Fiji at Twickenham on Saturday.
England boss Stuart Lancaster is due to name his starting line-up for the game tomorrow with Launchbury, who can play lock or flanker, seemingly set for a bench role.
Hailing Launchbury's new deal, Wasps rugby director David Young said: "This is fantastic news for us.
"It gives a real shot in the arm to all of our players and coaches as it's a vote of confidence in what we are trying to do here, and I am sure our supporters will be over the moon that someone of Joe's quality has signed on for the foreseeable future."
Launchbury, who joined Wasps from Worthing during the 2009-10 season, added: "I had no hesitation in extending my deal.
"There are some really good players for me to learn from here in our pack, and I feel very confident with the talent we have in the squad and the coaching set-up that we are part of something that is really building in a positive direction."