The New Zealand captain will move to the Warriors after the club confirmed a three-year deal for the 266-game veteran.
Blair played 74 games for the Broncos in three seasons, including the 2015 grand final against the Cowboys.
He captained the Broncos in eight matches in the past two years and demonstrated his durability by playing in all 27 matches for Brisbane this season.
Broncos’ chief executive Paul White thanked Blair for his contribution to the Broncos’ club and culture, and wished him and his family well as they return to his native New Zealand.
“He has been a leader for us both on and off the field and acted as a mentor to many of the young players across the club,” said White.
“His toughness and tenacity have really added something to our pack and we wish him all the best in the future.”
Blair will be named captain of the Kiwis’ squad for the 2017 Rugby League World Cup when they make their announcement tomorrow.
This was first published on the Brisbane Broncos website