North Shore Country Day School is a selective prep school in Winnetka, Illinois. It took its current form as a coeducational school in 1919 during the Country Day School movement, though it started as the Rugby School for Boys (1893-1900) and Girton School for Girls (1900-1918). It consists of a lower school, a middle school, and an upper school. North Shore Country Day School offers a liberal arts education with students representing the community's values of respect and inclusiveness.

Winnetka is a village in Cook County, Illinois, United States, located 16 miles (26 km) north of downtown Chicago. The population was 12,475 as of the 2020 census. The village is one of the wealthiest places in the United States in terms of household income. It was the second-ranked Illinois community on Bloomberg's 2019 Richest Places Annual Index.