England international Nathan Hughes will join Bristol Bears from Wasps at the end of the season while South Africa fullback Willie Le Roux is also set to leave the club, the Premiership side said on Tuesday.
Back-row Hughes has made 118 appearances for Wasps since making his debut in 2013 and has signed a three-year deal with the Bears, who were promoted to the top-flight last season.
"It's tremendous to secure Nathan's signing and to see how excited he is about coming to Bristol and helping us realise our vision," Bristol head coach Pat Lam said.
"At 27 years old, we're excited about how much better he can become as we continue to grow as a team.
"We are striving to be a Champions Cup team and a player of Nathan's quality can help us along our journey, on and off the field."
Le Roux has established himself as a key part of the Springboks since joining Wasps in 2016, where he has made 50 appearances.
Wasps, who have finished in the top four of the Premiership to qualify for the playoffs in each of the last three seasons, have also lost star winger Christian Wade this campaign after he quit rugby to pursue a career in the NFL.
"It's always disappointing to lose players of such quality but this is professional sport and there isn't much you can do about it," Wasps director of rugby Dai Young said.
"There are a number of factors that play a part in players' decisions to move on and unfortunately these guys have opted to move onto pastures new for 2019-20."