The 22-year old striker has been rewarded with a fresh 12-month deal and was thrilled to commit himself to the Dons for the foreseeable future.
"I have never hidden my desire to remain at Aberdeen so I am delighted to put pen to paper on a contract extension,” said the Northern Ireland international.
"It is a great club, with a unique set of fans and I hope next season I can repay the faith shown in me by everyone associated with Aberdeen FC.
"The squad is already looking forward to the season kicking off and I am certainly determined to play my part in bringing success back to Aberdeen."
Magennis arrived at Pittodrie from Cardiff City in 2010 and has since scored nine goals in 87 league appearances.