Montreal police spokeswoman Anie Lemieux said the head belonged to Jun Lin, who was killed and dismembered in May.
Luka Magnotta is accused of dismembering his lover Lin and mailing the body parts to Canadian political parties and schools. He pleaded not guilty to murder charges last month.
Lin's head was the only remaining missing body part until Sunday, when Lemieux said investigators found it in Park Angrignon after the major crimes unit received a tip. The park is a few miles (kilometers) south of Magnotta's apartment.
"It had been there for quite some time, but we won't go into details, partly out of respect for the family and friends of the victim," said Lemieux.