Sentencing Lee Brown to 10 years, Judge Richard Lowry QC, described his behaviour after hitting Nancy Joyce, 83, as 'defying description'.
David Waters, for the prosecution, had told the court at the Old Bailey that instead of stopping, Brown, 25, drove off at speed, running over Miss Joyce's body and dragging it more than 100 yards under the car. The jury was told that Miss Joyce - who was 4ft 9ins tall - might have survived had she had treatment after the initial impact.
The pensioner, who was known as the bird lady of Walworth, the south London area where she lived, was a popular figure and had been adopted as a granny by a local family.
She was killed as she walked to the park to feed pigeons. Birdseed was scattered all over the road when she was hit by Brown's car, the court was told.
Brown, of the Dickens Estate, Bermondsey, south London, was also banned from driving for 15 years.
At an earlier hearing, when he was remanded for reports, he had admitted manslaughter and driving a stolen car while disqualified in April this year.
The accident came three months after Brown was released on licence from prison, where he was serving time for offences which included reckless driving. In less than a month he was on bail for unlawfully taking a car. He was driving a Volkswagen Polo stolen by a friend when he hit Miss Joyce as she crossed the Old Kent Road.
John Boyle, a witness, told the court that 'she went straight up into the air about 12 feet'. He said Brown seemed to collide with another car then 'drove over her, one wheel on her chest and one wheel on her shin'.
'I could see people waving their arms and screaming 'you are killing her - stop'. There was no way the driver could not have known what was happening,' Mr Boyle said.
Brown later told police he was taking his girlfriend to buy heroin and not concentrating, as they were arguing.
Asked why he did not stop after the accident, he said he panicked and drove off because 'I was on a ban and was frightened'.
Brown's wheelchair-bound grandmother, Anne Mooney, 75, held her head in her hands and wept as he walked to the cells. She had earlier told the court that Brown had been badly affected by the death of his mother, who had died while he was in custody awaiting sentence.Reuse content