The skull was found Sunday by a walker, the Toronto Sun reported. York Police Constable Andy Pattenden said it was positively identified as Robert Hagans, 76.
Investigators do not believe Hagans was attacked, Pattenden said.
Hagans, a retired mechanical engineer, left home without taking any cash or his cell phone. He was seen walking nearby.
His three sons said at a news conference after the disappearance that Hagans had some memory loss and had sometimes wandered from home.