Police were dispatched to an apartment at 45 Baif Boulevard after a man went to a local hospital with injuries early Saturday morning.
A dead female was found inside the residence, police said. Forensic units are investigating the circumstances of the unidentified victim's death.
One man has been arrested in relation to the incident, but no charges have been laid.
Police say the investigation is ongoing and plan to release more information as it becomes available.
Anyone with potentially helpful information is asked to contact York Regional Police.