Pleasant Grove is a census-designated place (CDP) in Muskingum County, Ohio, United States.According to the United States Census Bureau, the CDP has a total area of 3.2 square miles (8.3 km2), of which 3.2 square miles (8.3 km2) is land and 0.31% is water.As of the census[3] of 2000, there were 2,016 people, 728 households, and 516 families residing in the CDP.There were 765 housing units at an average density of 239.6 per square mile (92.5/km2).23.4% of all households were made up of individuals, and 7.3% had someone living alone who was 65 years of age or older.