The suspect is expected to appear in court today.
On Saturday, Montreal police were called to an apartment on De Cobourg Avenue and found a 61-year-old man unconscious inside.
The man had suffered stab wounds to his upper body and was pronounced dead at the scene.
Police said the suspect was inside the apartment when officers arrived.
The relationship between the suspect and the victim hasn't been made public.
It is the eighth homicide of the year on Montreal police territory.