Sullivan County, New Hampshire

Sullivan County is a county in the U.S. state of New Hampshire. As of the 2010 census, the population was 43,742, making it the second-least populous county in New Hampshire. The county seat is Newport.

Sullivan County was founded in 1827 named for John Sullivan (1740–1795), the Revolutionary War hero and a former governor. It was formed from the northern part of Cheshire County.