Glastonbury High School is a public, co-educational high school located in Glastonbury, Connecticut, United States.

As the only high school in Glastonbury, it serves around 2,000 students and employs around 150 faculty members. As of 2023, the school ranks 1,158th out of a possible 17,680 high schools nationally and is ranked 23rd out of a possible 198 high schools in Connecticut.