The 25 year old, who spent the last half of the previous campaign with the Dons, is glad to have his future sorted out.
He told RedWeb: "I'm delighted to be returning to Aberdeen. I know the club, the manager and the players well so it's going to be an easy transition for me.
"I was desperate to get my future resolved and when it was made clear I wouldn't be part of the manager's plans at Sheffield Wednesday my thoughts turned to possibility of returning to Aberdeen.
"It's great to be back at Pittodrie where I feel wanted and I just can't wait to get my season started."