what county is monticello ny
Monticello, New York. Monticello /ËmÉntáµ»ËsÉloÊ/ is a village located in Thompson in Sullivan County, New York, United States. The population was 6,726 at the 2010 census. It is the seat for the Town of Thompson and the county seat of Sullivan County. The village was named after the residence of Thomas Jefferson.