Nevada County is a county located in the southwestern part of the U.S. state of Arkansas. As of the 2020 Census, the population was 8,310, less than half of its peak in 1920. The county seat is Prescott. Nevada County is Arkansas's 63rd county, formed during the Reconstruction era on March 20, 1871, from portions of Hempstead, Ouachita and Columbia counties. It was named after the state of Nevada because of the perceived similarity between their physical shapes; the Arkansas county's shape, inverted, roughly follows the same outline as the state's boundary. It is an alcohol prohibition or dry county.

The Little Missouri River, or Little Mo, is a 147-mile-long (237 km) waterway that runs from the Ouachita Mountains of southwest Arkansas into the rolling hills area in the surrounding countryside.