 According to the U.S. Census Bureau, the Knollwood CDP has an area of , all of it land.As of the 2010 U.S. Census, the population of Knollwood was 1,747 people, occupying 668 households.The racial makeup was 85.52% White, 4.81% Asian, 4.24% African American, 3.84% identifying as another race, and 1.60% identifying as two races or more.