The elderly man "was charged at" by the ram which launched a frenzied attack on him on a farm in the town of Cestas, south of Bordeaux, yesterday, police said.
The man was found dead, with a swollen and badly bruised face.
Investigators believe the ram knocked the man off balance, causing him to fall, and then trampled on him, inflicting more injuries.
"It was a young, one-year-old ram who is not at all aggressive -- my daughter reared him by bottle," the farmer who owns the animal told AFP, asking not to be named.
More From This Section
The man had been visiting the farm to talk to the farmer and had taken a short cut across the field when the incident took place.
Shortly afterwards, the sheep also charged at, and injured, a local politician, who rushed to the scene after hearing the news of the attack.
The female councillor suffered bruising but did not fracture her shoulder as was originally reported.
The sheep is expected to be put down.