The 26-year-old has been with Wasps since 2010 and has followed the likes of Elliot Daly, Tom Cruse, Ashley Johnson, Rob Miller and Alex Rieder in prolonging their stay at the Ricoh Arena in recent weeks.
The Exeter-born ace has become a vital player for the Coventry-based side, while also starring 46 times for England, and Wasps director of rugby Dai Young was pleased to secure his services.
"We know a number of sides would have been keen for Joe to join them," he said. "It is a mark of his loyalty and belief in the squad we are assembling."
Launchbury has made 117 appearances since his Premiership debut against Leicester in 2011 and, while the length of his extension is unknown, was relieved to get the business done.
"I'm really pleased to sign on again for a bit longer at the club," he said. "Over the past few weeks, it has been great to see a number of players signing new contracts, enabling the club to retain quality players.
"That reflects the belief we have in Dai and in our squad."