Stephen Terry Jeeves, aged 60, of Allhallows Leisure Park, Rochester, Kent, was convicted on Thursday (16/8) of four counts of indecent assault in Aylesbury Crown Court.
He was charged on 22 February for the offences that took place in the 1990s against a teenage girl in Kent and Aylesbury.
Jeeves denied the charges but was found guilty by unanimous verdict and was sentenced on Thursday.
Investigating officer DC Victoria Gidman, of Aylesbury police station, said: “This sentence reflects the severity of Jeeves’ crimes.
“Thames Valley Police take offences of this nature extremely seriously and will investigate thoroughly to bring offenders to justice.
“I would like to pay tribute to the victim in this case who very bravely gave evidence in court.”
Thames Valley Police were supported by Kent Police during the investigation.
Kent Police investigating officer DC John Milham said: “I would like to pay tribute to the victim in this case who, despite continuing to be very vulnerable, gave evidence at the trial in Aylesbury. Without her determination and courage to see this child abuser brought to trial we would not have been able to gain the conviction of this man.
“Kent Police will thoroughly pursue any child sex offender, whether the crimes were committed recently or many years ago and I would encourage those who have been victims of this type of crime, or those who believe they know a child is or has been abused to report it to us.”