Locust Valley High School is a public high school located in Lattingtown, Nassau County, New York, U.S.A., and is the only high school operated by the Locust Valley Central School District.As of the 2014-15 school year, the school had an enrollment of 716 students and 45.3 classroom teachers (on an FTE basis), for a student–teacher ratio of 15.8:1. There were 81 students (11.3% of enrollment) eligible for free lunch and 21 (2.9% of students) eligible for reduced-cost lunch.