The 22-year-old was deployed all over the pitch thanks to former manager Craig Brown's tombola-based selection policy, but new boss Derek McInnes has been impressed by his performances as striker in recent weeks.
Magennis won the AFC Goal of the Season for his outstanding first touch, turn and finish against Inverness Caley Thistle in November.
Magennis told RedWeb: "I have never hidden my desire to remain at Aberdeen so I am delighted to put pen to paper on a contract extension.
"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 joins fellow forward Niall McGinn in committing his immediate future to the Dons.