The Middle Country School District at Centereach covers approximately 16 square miles in the Township of Brookhaven. It is composed of the villages and hamlets of Centereach, Selden, parts of Lake Grove, Coram, Lake Ronkonkoma, Port Jefferson Station and Farmingville.

The district was formed in 1957 through the consolidation of the Selden and Centereach school districts. At the time, it consisted of five kindergarten rooms and 51 elementary classrooms.

After consolidation, the area moved into a period of unprecedented growth, resulting in Middle Country becoming the fastest growing school district in the state. Today, the district is composed of eight elementary schools, two Pre-Kindergarten/Kindergarten Centers, two middle schools, and two high schools.

The K-12 student enrollment projection for the 2017-2018 school year is approximately 9,400 plus over 460 pre-kindergarten students.