private, coeducational, college-preparatory school (grades 9–12) in Exeter, N.H., U.S. It was founded as a boys' school in 1781 by John Phillips, a local merchant and uncle of Samuel Phillips, the founder three years earlier of Phillips Academy in Andover, Mass.

Exeter's curriculum emphasizes group discussion led by the instructor in a Socratic manner—an instructional method called the Harkness Plan, for philanthropist Edward S. Harkness, who richly endowed the school in 1931. Exeter has gained a national reputation for faculty participation in decision making and for freedom of speech, and in 1953 an Exeter Study Commission under the direction of William Saltonstall issued a report that led to a national reexamination of the role of secondary education. The school began admitting girls in 1970.