Saracens have agreed a £32m takeover deal with a consortium of investors that includes South African World Cup-winning former captain Francois Pienaar.
The group will acquire a majority controlling stake in the club.
Nigel Wray, the club's owner for 26 years, retains "a significant minority shareholding, albeit a passive one", a club statement said.
Chairman Neil Golding and chief executive Lucy Wray will remain.
Pienaar, who led the Springboks to victory at the 1995 World Cup, made 44 appearances as a player-coach for Saracens.
Marco V. Masotti, the owner of South Africa's Sharks rugby team, is also part of the six-person consortium.
Saracens say the money brought in by the investors will help the club "maintain their position at the top of the men's game".
Saracens were given a 35-point deduction and £5.36m fine in 2019 for breaching the league's salary caps.
They were subsequently relegated from the Premiership at the end of the 2019-20 season, but won promotion back in the next season.
"I have given my heart and soul to the club for more than two decades, having chaired Saracens since the first days of professionalism," Nigel Wray said.
"Sadly, I'm not getting any younger and I have always wanted to make sure that Saracens is in very safe hands for many future generations."
Former England and Saracens women's player Maggie Alphonsi has been added to the club's board.
Michael Yormark, president of sports management agency Roc Nation Sports International, has also been named as a special adviser.
A club statement said the investment would be used for a number of improvements at the club, including redeveloping the West Stand, further investing in women's sport and creating a high performance training centre.
"I am thrilled to hand over control to the consortium which comprises people who I know well and who understand the culture we've been able to create over more than 20 years both on and off the field," Wray added.
"I am looking forward to becoming just a fan again and supporting the club I love."