Niagara police were called to a home in area of Collier Street and Westchester Avenue in St. Catharines just before 11:00 Saturday morning for a welfare check.
When they arrived, they found a 53-year-old man in distress.
He was taken to hospital where he was pronounced dead a short time later.
Police say 28-year-old Alexander Windsor of Welland is scheduled to appear at a bail hearing Sunday on a charge of second degree murder.
No other details about the case were immediately released.