Holmes County is one of the 88 counties of the US State of Ohio. The county seat is Millersburg, and its largest city is Millersburg. The county has an area of 1,098 km², the population of 38,943 inhabitants, and the population density is 36 inhab / km². This county was founded in 1825. It is famous for having the largest concentrations of Amish in the United States.