Mark Westwater, 33, from Blackpool was sentenced at Leeds Crown Court for sexual offences against four victims.
Among the crimes he was sentenced for was a sexual offence on a then eight-year-old girl in the Castleford area.
The offence took place in autumn 2016 and came to police attention after the victim disclosed the offence to adults.
He was identified and arrested shortly afterwards and was charged with the offence in April 2017.
Westwater was sentenced to eight years in prison for the offence on the Castleford victim.
He was also sentenced for a total of 11 non-recent offences against three other children from outside the West Yorkshire area, giving him a total time in prison of 30 years.
Westwater was told he must serve a minimum 20 years before he will be considered for parole.
Det Insp Charlie Manson of the Wakefield District Child Safeguarding Unit, said: “We welcome the sentencing of Westwater and the fact that he will clearly be spending many years behind bars.
“Wakefield District Police investigated his offending in West Yorkshire, and in that case he abused the trust of those around him and committed a sexual offence against a very young victim.
“She showed real courage in disclosing what had happened to her.
“We fully recognise how difficult disclosing these offences can be for both the victim and those around them and promise those who come forwards will be treated with the utmost sensitivity by specially trained child protection officers.”