Acton-Boxborough Regional High School (ABRHS) is an open enrollment high school in Acton, Massachusetts. It serves the Massachusetts towns of Acton and Boxborough and has students in grades 9 through 12. It is situated downhill from the Raymond J. Grey Junior High School, at 36 Charter Road in Acton. Raymond J. Grey Junior High School occupies the facility that, until 1973, was the high school. ABRHS underwent an $80 million renovation and expansion in 2005.