John Marshall Harlan High School is the eleventh public high school in the Northside Independent School District of San Antonio, Texas and classified as a 6A school by the University Interscholastic League. During 20222023, Harlan High School had an enrollment of 2,532 students and a student to teacher ratio of 17.12. The school received an overall rating of "B" from the Texas Education Agency for the 20242025 school year.
It is named after U.S. Supreme Court justice John Marshall Harlan. It is NISD's 11th comprehensive high school. The building, with a cost of $110 million, is NISD's largest school campus. It opened on August 28, 2017.