Sidney Rayner was responsible for the repeated abuse between 2003 and 2007 in the Brenchley area.
Kent Police was first alerted to allegations of child sex offences in 2018, and a subsequent investigation revealed Rayner had systematically targeted his young victim.
Rayner, of Dyserth Road, Chester in Cheshire was interviewed and denied the allegations. He was later charged with five sexual offences including three counts of sexual assault of a child.
The 82-year-old pleaded guilty at Maidstone Crown Court and, on Tuesday 3 November 2020, he was jailed for seven years and six months. He was also made subject of a sexual harm prevention order and added to the sex offenders’ register for life.
Detective Constable Deniz Aslan, of Kent Police’s Paedophile and On-Line Investigation Team, said: ‘Rayner repeatedly abused a vulnerable child over several years and acted in a despicable way. He is a predatory paedophile and has caused intolerable suffering.
‘Rayner has finally been brought to justice through the courage of his victim and a period in prison will ensure he can cause no further harm to other young children.‘