The fire department said three crews were dispatched at about 12:35 p.m. to a two-storey house on 3rd Avenue near Gouin Boulevard, a building with three apartments inside.
Two people in the house escaped without injury, but the elderly man was found with no pulse or respiration and with burns to his face, Urgences Santé said.
"It was an 82-year-old male who was in cardiac arrest due to the fire," said David Sasson, a spokesperson for the ambulance service.
Paramedics tried to resuscitate him while he was taken to Sacré-Coeur Hospital, but it was to no avail, and he was declared dead around 1:50 p.m.
Two women — the man's wife and and a women who lived in the downstairs unit — were taken to hospital suffering from shock.
Neighbour Claude Sanon said he had chatted with the man earlier in the morning.
"We often talked. This morning, before I went out, he was on his balcony. We said hi to each other, how's it going. When I came back, I saw a woman crying and screaming. The smoke was all over, really high," Sanon said in French.
"He was a nice man. We got along well."
Fire department operations chief Francis Leduc said the flames began in the kitchen, destroying the first floor and eventually spreading to the second storey and roof. It took more than 60 firefighters until 2 p.m. to put out the blaze.
He said fire investigators are still looking into what caused the fire.