Northbrook is a census-designated place (CDP) in Hamilton County, Ohio, United States. The population was 10,668 at the 2010 census.GeographyNorthbrook is located at.According to the United States Census Bureau, the CDP has a total area of 1.9sqmi, all land.DemographicsAs of the census of 2000, there were 11,076 people, 4,179 households, and 2,996 families residing in the CDP. The population density was 5,713.1 people per square mile (2,204.4/km2). There were 4,290 housing units at an average density of 2,212.8/sq mi (853.8/km2). The racial makeup of the CDP was 82.15% White, 14.16% African American, 0.35% Native American, 0.97% Asian, 0.09% Pacific Islander, 0.57% from other races, and 1.72% from two or more races. Hispanic or Latino of any race were 1.56% of the population.There were 4,179 households out of which 34.7% had children under the age of 18 living with them, 51.0% were married couples living together, 15.7% had a female householder with no husband present, and 28.3% were non-families. 23.8% of all households were made up of individuals and 9.0% had someone living alone who was 65 years of age or older. The average household size was 2.65 and the average family size was 3.13.