Launchbury came through Harlequins’ academy before moving to Wasps at the start of his career.
He went on to make 170 appearances and captain the side over a 12-year period, before the club folded in 2023.
After a brief spell playing in Japan for Toyota Verblitz he returned to the Prem with Harlequins.
On the international stage, Launchbury made his England debut in 2012 and a year later was named England player of the year.
He was part of the side that reached the World Cup final in 2019, and won the Six Nations Grand Slam in 2016.
Launchbury, who is currently out with a short-term quad injury, said he would “love to stay involved in the game”.
“But for now I am looking forward to what comes next, and most of all being present to watch my children grow up,” he added.
Harlequins head coach Jason Gilmore said Launchbury had “consistently set the standard”.
“A quality operator on the field and an even better man off it, Joe has consistently set the standard with his exceptional leadership and professionalism,” he said.
“His impact for club and country in English rugby over a long period of time in such a demanding position demonstrates what a great servant he has been.”
