Paul Griffiths, 49, from Knottingley, carried out repeated attacks between 2010 and 2015 on a girl aged under 10.
Police today said he posed a “significant danger” to children, adding that his crimes were some of the most serious they had encountered.
Griffiths was arrested in October 2015 after his victim revealed the abuse to a relative who then went to the police.
He was sentenced at Leeds Crown Court on Tuesday after being convicted of rape and other sexual offences.
Det Con Victoria Bottomley, who led the investigation, said: “We are pleased Griffiths has received such a substantial sentence for extremely serious crimes committed against a very young and vulnerable child.
“Griffiths targeted and then committed multiple sexual offences against her over a sustained period, behaving in a truly appalling fashion in which he took advantage of a youngster who was in no position to stop him.
“The crimes he committed were as serious as we see here as safeguarding detectives and it is no exaggeration to say he poses a significant danger to children.”
She added: “I wish to commend the courage of the young victim in disclosing these offences, and then telling officers what happened in subsequent police interviews.”
DC Bottomley also urged any victims of sexual offences to contact the police, saying: “We always listen and investigate.”