Scotland captain Barclay joins Edinburgh
Barclay, 31-years-old, has spent the past four years in Llanelli and will join Edinburgh at the end of the current season.
The back row forward, who started his career at Glasgow, has been capped 64 times by his country and is captaining the team in the absence of the injured Greig Laidlaw.
"Edinburgh as a club, and as a city, has a huge amount of potential and I can see what they are trying to do, so I'm looking forward to being a part of it," Barclay told the Edinburgh website.
"Scotland is home, so it'll be great to come back and play at one of my home regions,"