Ward Melville High School is a public high school in the Three Village Central School District of Suffolk County, New York on Long Island, serving grades nine through twelve. It is fed by the two junior high schools in the district: Paul J. Gelinas Junior High School and Robert Cushman Murphy Junior High School, and is named after businessman and philanthropist Ward Melville.

Located sixty miles from Manhattan in the Three Village area, Ward Melville High School is situated in East Setauket, New York. The school serves students from Setauket, East Setauket, Stony Brook, Old Field, Strongs Neck, Poquott, and South Setauket.

As of the 2011–12 school year, the school had an enrollment of 1,848 students and 140.0 classroom teachers (on an FTE basis), for a student-teacher ratio of 13.2.

The building was originally designed to have 290,700 square feet (27,010 m²) with capacity for 2,000 students, although it has been expanded several times since. Each of the three grades currently has approximately 600 students.

The district provides for numerous clubs and activities after school, including a musical–theater arts program and many sports teams. The school offers 25 different Advanced Placement courses and another 25 college courses that are offered credit through several colleges and universities.

The school has been expanded several times to accommodate the growing number of students attending Ward Melville High School. In 2002, two extra wings were added to the northeastern and southeastern corners of the school. During the 2009–2010 school year, a new weight training facility was completed in the rear of the school while the music rooms were renovated. In the 2010–2011 school year, an additional wing was built to house the science department while the auditorium and the library was refurbished.