Scott Brown will call time on his 14-year career with Celtic in the summer to team up with new Dons manager Stephen Glass at Pittodrie.
The former Hoops captain is the first signing made by Glass, who was unveiled as Derek McInnes’ replacement, on Tuesday.
Brown, 35, will pen two-year deal, giving him the chance to prolong his playing career while also offering the move into coaching he craves.
Aberdeen confirmed the news on their website.
Central midfielder Brown, a former Scotland captain who has won 22 domestic trophies with the Parkhead club, said: “There is no doubt I had a lot to deliberate when deciding my next steps, particularly after enjoying fourteen successful years at Celtic.
“However, the opportunity to join Aberdeen, a club entering an exciting new period with my former team-mate Stephen now at the helm, was one I couldn’t pass up.
“Once this season concludes, I’m looking forward to joining Stephen, the playing and coaching staff and everyone at Aberdeen FC.
“I am totally committed to the challenge that lies ahead in meeting the ambitions of the club and its fans.
“I still feel I have got a lot to give, not only on the pitch, but in a broader capacity as I embark on my coaching journey. I will be relentless in my quest for success for Aberdeen.”
Glass said: “The opportunity to bring a player of Scott’s calibre, a leader who has more European appearances for Celtic than any other player, is a huge coup for me and for Aberdeen.
“His experience will be invaluable on the pitch and he is someone who will help set the standards we expect at this club. A born competitor, with a strong appetite to win, his hands-on approach and desire to nurture will hugely benefit the development of the young, emerging talent we have here.
“Scott will be a big part of my coaching team and, whilst his impact will undoubtedly be felt on the pitch where I believe he still has much to give, I am looking forward to assisting his transition into coaching.
“He is excited about coming to Aberdeen and working with the current playing, and wider coaching and support staff already in place.
“I’ve no doubt he will be a success here.”