Police have arrested an 18-year-old woman in the macabre killing of man whose corpse was wrapped in a plastic bag and discovered on the roof of a Bronx McDonald’s.

Cops identified the suspect as Ayame Stamoulis, of Brooklyn. She’s charged with murder, police said.

The body of the man was found Wednesday on top of the restaurant on East 149th Street near the Grand Concourse just before 6 a.m., police said.

A 911 caller told police that only half a body was on the roof, according to police sources — though authorities at the time could not immediately confirm that gruesome detail.