Groton School is a private, college-preparatory, day and boarding school located in Groton, Massachusetts, United States. It is affiliated with the Episcopal tradition.

Groton enrolls about 380 boys and girls from the eighth through twelfth grades, dubbed Forms II–VI in the British fashion. Its $475 million endowment enables the school to admit students on a need-blind basis. Typically, 40–44% of students are on financial aid. Students with family incomes under $150,000 attend for free.

The school admitted 8% of applicants in 2022. Its list of notable alumni includes U.S. President Franklin D. Roosevelt and Nobel laureate John B. Goodenough.