Serial killer Charles Manson has been granted permission to marry a woman 54 years his junior who visits him in prison.

The 80-year-old was locked up for life after being found guilty of murdering at least seven people in the late Sixties, including Roman Polanski's wife Sharon Tate, who was eight months pregnant with their child at the time.

But yesterday he successfully obtained a marriage licence allowing him to wed Afton Elaine Burton.

Burton, 26, who goes by the name "Star," told the Associated Press she and Manson will be married next month.

She said: "Y'all can know that it's true. It's going to happen. I love him."

Manson's bride-to-be moved to California nine years ago to be near the prison Manson is in.

She also maintains several websites advocating Manson's innocence.

Burton claims the wedding might have happened earlier if Manson did not have "some situations" at the prison.

California Department of Corrections spokeswoman Terry Thornton said Manson had three violations for possession of a weapon, threatening staff and refusal to provide a urine sample.

The prison holds weddings on the first Saturday of each month.

Manson and his prospective spouse would also be allowed to invite 10 guests who are not inmates.

However, as a life prisoner with no parole date, he is not entitled to conjugal visits.

Charles Manson's last prison mugshot from 2012. Credit: Reuters

Manson has been incarcerated since the infamous Tate-LaBianca murders in 1969.

Although he never committed any of the murders himself, he incited his self-styled "Manson family" to carry out his evil acts.

He and two women followers, Leslie Van Houten and Patricia Krenwinkel, remain imprisoned. Another follower, Susan Atkins, died of cancer behind bars.

Manson is not eligible for parole until 2027.