Deerfield Academy is an independent, coeducational boarding school in Deerfield, Massachusetts, United States. It is a four-year college-preparatory school with approximately 640 students and about 120 faculty, all of whom live on or near campus during the school year. Deerfield is a member of the Eight Schools Association (ESA), begun informally in 1973–74 and formalized in 2006, and of the Ten Schools Admissions Organization, founded in 1956.