Hall, 84, from Wilmslow, Cheshire, will start the sentence after completing a 30-month term for similar offences.
He admitted indecently assaulting the girl when she was 13 and was found guilty of one count in a majority jury verdict at Preston Crown Court.
He was cleared of 15 rape charges and four indecent assaults.
The charge Hall admitted involved an incident at a dinner party where he crept into his victim's bedroom and assaulted her.
Sentencing him, Mr Justice Turner, said there had been "an element of grooming" to his offences.
Mr Justice Turner said there had been a "breach of trust" in relation to the assault on the girl when she was 13.
He said that Hall had acted with "a sense of arrogance and immunity... vile bravado and horrible betrayal".
He added that the 84-year-old had shown "a lack of candour or remorse" and criticised him for not admitting to these offences when he was convicted of other offences in 2013.
Hall did not react to the sentence as he listened to the proceedings through headphones, while his victim, who was also in court, wiped away tears with a handkerchief as details of the offences were mentioned.
The former broadcaster, who was accused of abusing two girls between 1976 and 1981, is already serving a 30-month jail term after he pleaded guilty to indecently assaulting 13 other girls, one as young as nine.
His original 15-month sentence, for abuse that occurred between 1967 and 1985, was later doubled at the Court of Appeal.
Speaking after the hearing, the Chief Crown Prosecutor for the North West, Nazir Afzal, said Hall's convictions "were only made possible by the courage of his victims".
"I would like to thank them for coming forward and ensuring that he was brought to justice," he said.
Ex-BBC broadcaster Stuart Hall has been sentenced to an extra two years and six months in prison for two counts of indecently assaulting a girl.