James I. O'Neill High School opened in 1971, replacing the existing Highland Falls High School on Mountain Avenue in Highland Falls.

[3] In September 2004 O'Neill was still taking students from Saint Basil Academy who were not from families resident in New York State.

[4] In 2021, 190 children living on-post at United States Military Academy (USMA) in West Point attended O'Neill.

It includes the village of Highland Falls and the hamlets of Fort Montgomery and West Point.

[9] Additionally, USMA sends high school aged students who are dependents of on-base military personnel to O'Neill under contract.