Police were called out to a home on Clancy Drive, near Van Horne Avenue and Don Mills Drive, at 2:18 p.m. on Saturday.
When officers arrived at the scene, they found a woman "suffering from apparent trauma to the body," according to a police news release issued Sunday.
Paramedics transported the woman to a hospital with life-threatening injuries. She was later pronounced dead.
Police have still not released the victim's name.
Mohamed Adam Bharwani, 18, is charged with first-degree murder. He appeared in court on Sunday.