The Rockland County District Attorney's Office said 70-year-old Thomas Kelly of Chestnut Ridge was sentenced to 12 years in prison.
He pleaded guilty to sexually abusing a girl younger than 13 between June 2019 and February 2020.
Kelly was also sentenced to 10 years of probation and must register as a sex offender upon his release from prison.
The victim was granted a full stay-away order of protection.