A secondary school is one means of delivering education to adolescents in level 2 or junior secondary education, which is considered the second and final phase of basic education, or level 3 (Upper) secondary education phases on the ISCED scale. Every country aims to provide schools for basic education, but the systems and terminology remain unique to them. Secondary schools typically follow on from primary schools Attendance is compulsory in most countries for students between the ages 11 and 16.

In the United States, the term ‘secondary school’ can refer to several types of schools. The first type is a traditional, comprehensive high school, comprising grades 9–12. Another type is alternative schools, including continuation schools, which serve those same grades. In some jurisdictions, ‘secondary school’ may refer to an institution that houses grades 7–12. The term ‘secondary school’ also categorically includes both middle school and high school. This page lists many secondary schools in the United States.