Bentonville is a census-designated place in northern Sprigg Township, Adams County, Ohio, United States. The population was 253 at the 2020 census. It has a post office with the ZIP code 45105. Bentonville is located on State Routes 41 and 136. They run concurrently through the community, splitting into separate routes at the south edge of Benton…Bentonville is a census-designated place in northern Sprigg Township, Adams County, Ohio, United States. The population was 253 at the 2020 census. It has a post office with the ZIP code 45105. Bentonville is located on State Routes 41 and 136. They run concurrently through the community, splitting into separate routes at the south edge of Bentonville.