The first high school in Blackstone was built in 1868 on School Street. It was replaced in 1920 with a new high school on Main Street. The Main Street building was expanded in 1938. As population in the area grew, regionalization was discussed as a way to provide a new high school for Blackstone and Millville. The Blackstone-Millville Regional School District, which regionalized grades 7-12, was approved by voters in both towns in 1967 and charged with planning and establishing a regional junior-senior high school to be located on Lincoln Street in Blackstone. Following the sale of school district construction bonds, Blackstone-Millville Junior-Senior High School opened its doors in September 1970 serving students in grades 7 through 12 and the former high school building was retained by the district for use as an intermediate elementary school. Blackstone and Millville maintained separate K-6 school committees until 1982, when school budget cuts resulting from Massachusetts
Proposition 2½ going into effect pushed the towns to work out a plan to modify the regional district to establish a K-12 regional district, approved by voters at Special Town Meetings in April 1982. The Blackstone-Millville Regional School District began operating as a K-12 regional district on July 1, 1982. When Frederick W. Hartnett Middle School opened in 2003, the high school realigned to serve students in grades 9 through 12. ==School demographics==