Bradley Davies will leave Wasps at the end of the Premiership season after agreeing a National Dual Contract (NDC) with Wales and Ospreys.
The lock has spent the past two seasons in England after making the switch from Cardiff Blues in 2014 and could cap his departure with the Premiership title in the coming weeks with Wasps in the semi-finals.
Davies has now opted to return to Wales and will join Ospreys ahead of the next Pro12 season.
"I'm really pleased to have signed a National Dual Contract and to be linking up with the Ospreys," said the 29-year-old.
"I would like to thank Wasps for the last couple of years, I have really enjoyed my time at the club and I'm looking to finish on a high over the next couple of weekends.
"For me though the opportunity to return to Wales on NDC was too good to turn down, the contracts focus on getting the best out of the players and provides support on and off the field and that is really important.
"I'm excited to be joining the Ospreys, it will be a fresh start for me, the region has big ambitions and I want to play a part in that. It will be great to team up with the likes of Alun Wyn [Jones] and the wealth of young Welsh second rows at the region.
"I'm not returning to Wales to retire, I want to push on and the NDC and the Ospreys allow me to do that."
Davies has established himself as a key member of Wales' squad and has made 54 appearances since his debut in 2009, while he also appeared in all five matches of this year's Six Nations as Warren Gatland's men finished runners-up to England.
And Gatland is thrilled by Davies' decision, adding: "It is great to see Bradley returning to Wales to play his club rugby and to have signed a NDC.
"It is important we create an environment that is attractive to our players and I believe with the number of players retained and returning we are getting on the right track."