Sycamore High School is a public high school in Sycamore, Illinois, United States. The school is a member of the Illinois High School Association and is a part of Sycamore Community Unit School District #427. Sycamore High School is the only school in the city and serves students in grades 9–12 living in Sycamore and the surrounding areas. Sycamore High School is also a founding member of the Northern Illinois Big 12 Conference.