The nature of his death is not yet known but police have confirmed that it was not a shooting or a stabbing.
The man, whose age and identity have yet to be revealed, was found by a woman living in one of the flats across to the road.
Emergency services were called at around 10.45am to reports of a man collapsed on the street and he was pronounced dead at 11.35pm after attempts by parademics to revive him failed.
A small patch of grass remained cordoned off this morning, with a CSI van and a police car at the scene. Another police car was stationed a little further up Blackstock Road but it is not known whether this was connected.
Residents living in the block of flats outside which the man was found dead told this morning how the news had left them shocked and heartbroken.
One person said: “It’s shocking. It’s Gleadless Valley but there’s been nothing untoward recently.
“Police came knocking at about 12.45am this morning but I don’t think anyone in this block knows anything about the circumstances.”
Another resident said: “It’s awful. It’s just heartbreaking.”
Anyone with information is asked to call South Yorkshire Police on 101, quoting the incident number 1016 of August 7.
Sheffield residents speak of shock after man tragically found dead on grass verge outside flats