Diamond City is a city in Boone County, Arkansas, United States. The population was 782 at the 2010 census. It is part of the Harrison Micropolitan Statistical Area.GeographyDiamond City is located at .According to the United States Census Bureau, the city has a total area of 2.68sqmi, all of it land.Major highway20px Arkansas Highway 7 Arkansas State Highway 7 reaches its northern terminus at Bull Shoals Lake at the northern edge of Diamond City, AR., at a state maintained park and privately owned marina's.DemographicsAs of the census of the year 2000, there were 730 people, 346 households, and 235 families residing in the city. The population density was 272.9 people per square mile (105.2/km²). There were 547 housing units at an average density of 204.5 per square mile (78.8/km²). The racial makeup of the city was 96.71% White, 0.55% Native American, and 2.74% from two or more races. 1.37% of the population were Hispanic or Latino of any race.