"He's a proven leader on and off the field who sets the kind of example we want all our players to aspire to, the epitome of the professional athlete who demands the highest of standards highlighted by an ultra-competitive attitude."
Warriors coach Stephen Kearney, who worked closely with Blair at the Kiwis, Melbourne Storm and Broncos, is excited to have the experienced player on board.
"Adam is a wonderful example of how a player should go about his business in the NRL as well as representing his country.
"He has had a tremendous career and he's going to be a huge asset for the club as we go about lifting our standards across the board."
Blair, who has played in 266 NRL games, is the fourth signing for the Warriors in an aggressive off-season as they look to improve on their woeful 13th place in 2017.
He will join new teammates Tohu Harris, Gerard Beale and Leivaha Pulu in the side for 2018.