[3] The 220-acre (0.89 km2) campus borders the village green of Washington, a small, historic town in Litchfield Hills.

During World War II, The Gunnery prepared boys for entering the armed forces.

For several years prior, The Gunnery had a partnership with the nearby all-girls school Wykeham Rise, which has since closed.

Each dormitory consists primarily of single and double student rooms, but also house faculty and their families.

There are students from 22 countries and 22 states in the U.S. Students from the Bahamas, Bahrain, Bermuda, Brazil, Canada, China, Germany, Hong Kong, Hungary, India, Korea, Mexico, Moldova, Saudi Arabia, Spain, Sweden, the United Kingdom, Vietnam and the U.S. Virgin Islands were included in the student body in the 2021–22 academic year.